Introducing security requirements during the initiation phase would BEST ensure that security is integrated during application development because it would allow the security objectives and controls to be defined and aligned with the business needs and risk appetite before any design or coding is done. This would also facilitate the security by design approach, which is the most effective method to enhance the security of applications and application development activities1. Introducing security requirements early would also enable the collaboration between security professionals and developers, the identification and specification of security architectures, and the integration and testing of security controls throughout the development life cycle2. Employing global security standards during development processes (A) would help to ensure the consistency and quality of security practices, but it would not necessarily ensure that security is integrated during application development. Providing training on secure development practices to programmers (B) would help to raise the awareness and skills of developers, but it would not ensure that security is integrated during application development. Performing application security testing during acceptance testing would help to verify the security of the application before deployment, but it would not ensure that security is integrated during application development. It would also be too late to identify and remediate any security issues that could have been prevented or mitigated earlier in the development process. References = 1: Five Key Components of an Application Security Program - ISACA1; 2: CISM Domain - Information Security Program Development | Infosec2

The most effective way to help staff members understand their responsibilities for information security is to require them to participate in information security awareness training. Information security awareness training is a program that educates and motivates the staff members about the importance, benefits, and principles of information security, and the roles and responsibilities that they have in protecting the information assets and resources of the organization. Information security awareness training also provides the staff members with the necessary knowledge, skills, and tools to comply with the information security policies, procedures, and standards of the organization, and to prevent, detect, and report any information security incidents or issues.
Information security awareness training also helps to create and maintain a positive and proactive information security culture among the staff members, and to increase their confidence and competence in performing their information security duties.
References = CISM Review Manual, 16th Edition, Chapter 1: Information Security Governance, Section:
Information Security Culture, page 281; CISM Review Manual, 16th Edition, Chapter 3: Information Security Program Development and Management, Section: Information Security Awareness, Training and Education, pages 197-1982.

A capability maturity model evaluation is the best way to determine the gap between the present and desired state of an information security program because it provides a systematic and structured approach to assess the current level of maturity of the information security processes and practices, and compare them with the desired or target level of maturity that is aligned with the business objectives and requirements. A capability maturity model evaluation can also help to identify the strengths and weaknesses of the information security program, prioritize the improvement areas, and develop a roadmap for achieving the desired state.
References = Information Security Architecture: Gap Assessment and Prioritization, CISM Review Manual
15th Edition

Secure transmission protocols are network protocols that ensure the integrity and security of data transmitted across network connections. The specific network security protocol used depends on the type of protected data and network connection. Each protocol defines the techniques and procedures required to protect the network data from unauthorized or malicious attempts to read or exfiltrate information1. One of the most common threats to network data is eavesdropping, which is the interception and analysis of network traffic by an unauthorized third party. Eavesdropping can compromise the confidentiality, integrity, and availability of network data, and can lead to data breaches, identity theft, fraud, espionage, and sabotage2. Therefore, secure transmission protocols protect transactions from eavesdropping by using encryption, authentication, and integrity mechanisms to prevent unauthorized access and modification of network data. Encryption is the process of transforming data into an unreadable format using a secret key, so that only authorized parties can decrypt and access the data. Authentication is the process of verifying the identity and legitimacy of the parties involved in a network communication, using methods such as passwords, certificates, tokens, or biometrics. Integrity is the process of ensuring that the data has not been altered or corrupted during transmission, using methods such as checksums, hashes, or digital signatures3. Some examples of secure transmission protocols are:
* Secure Sockets Layer (SSL) and Transport Layer Security (TLS), which are widely used protocols for securing web, email, and other application layer communications over the Internet. SSL and TLS use symmetric encryption, asymmetric encryption, and digital certificates to establish secure sessions between clients and servers, and to encrypt and authenticate the data exchanged.
* Internet Protocol Security (IPsec), which is a protocol and algorithm suite that secures data transferred over public networks like the Internet. IPsec operates at the network layer and provides end-to-end security for IP packets. IPsec uses two main protocols: Authentication Header (AH), which provides data integrity and authentication, and Encapsulating Security Payload (ESP), which provides data confidentiality, integrity, and authentication. IPsec also uses two modes: transport mode, which protects the payload of IP packets, and tunnel mode, which protects the entire IP packet.
* Secure Shell (SSH), which is a protocol that allows secure remote login and command execution over insecure networks. SSH uses encryption, authentication, and integrity to protect the data transmitted between a client and a server. SSH also supports port forwarding, which allows secure tunneling of other network services through SSH connections.
References = 1: 6 Network Security Protocols You Should Know | Cato Networks 2: Eavesdropping Attacks - an overview | ScienceDirect Topics 3: Network Security Protocols - an overview | ScienceDirect Topics : SSL
/TLS (Secure Sockets Layer/Transport Layer Security) - Definition : IPsec - Wikipedia : Secure Shell - Wikipedia

The best step to address the situation of losing a smartphone that contains sensitive information is to remotely wipe the device, which means erasing all the data on the device and restoring it to factory settings. Remotely wiping the device can prevent unauthorized access to the sensitive information and protect the organization from data breaches or leaks. Remotely wiping the device can be done through services such as Find My Device for Android or Find My iPhone for iOS, or through mobile device management (MDM) solutions. The other options, such as disabling the user's access, terminating the device connectivity, or escalating to the user' s management, may not be effective or timely enough to secure the sensitive information on the device.
References:
https://www.security.org/resources/protect-data-lost-device/
https://support.google.com/android/answer/6160491?hl=en
https://www.pcmag.com/how-to/locate-lock-erase-how-to-find-lost-android-phone