The primary reason for an IS auditor to use data analytics techniques is to reduce detection risk. Detection risk is the risk that an IS auditor will fail to detect material errors or irregularities in the information systems environment. By using data analytics techniques, such as data extraction, analysis, visualization, and reporting, an IS auditor can enhance the audit scope, coverage, efficiency, and effectiveness. Data analytics techniques can help an IS auditor to identify anomalies, patterns, trends, correlations, and outliers in large volumes of data that may indicate potential issues or risks. Technology risk, control risk, and inherent risk are types of audit risk that are not directly affected by the use of data analytics techniques by an IS auditor. References: [ISACA Journal Article: Data Analytics for Auditors]

The greatest concern to an IS auditor reviewing an organization's method to transport sensitive data between offices is that the method relies exclusively on the use of asymmetric encryption algorithms. Asymmetric encryption algorithms, also known as public key encryption, use two different keys for encryption and decryption: a public key that is shared with anyone who wants to communicate with the sender, and a private key that is kept secret by the sender. Asymmetric encryption algorithms are more secure than symmetric encryption algorithms, which use the same key for both encryption and decryption, but they are also slower and more computationally intensive. Therefore, relying exclusively on asymmetric encryption algorithms may not be efficient or practical for transporting large amounts of sensitive data between offices. A better method would be to use a combination of symmetric and asymmetric encryption algorithms, such as using asymmetric encryption to exchange a symmetric key and then using symmetric encryption to encrypt and decrypt the data.
The other options are not as concerning as option C. The method relying exclusively on the use of public key infrastructure (PKI) is not a concern, because PKI is a system that provides the services andmechanisms for creating, managing, distributing, using, storing, and revoking digital certificates that are based on asymmetric encryption algorithms. PKI enables secure and authenticated communication between parties who do not have a prior trust relationship. The method relying exclusively on the use of digital signatures is not a concern, because digital signatures are a way of verifying the authenticity and integrity of a message or document by using asymmetric encryption algorithms. Digital signatures ensure that the sender cannot deny sending the message or document, and that the receiver can detect any tampering or alteration of the message or document. The method relying exclusively on the use of 128-bit encryption is not a concern, because 128-bit encryption is a level of encryption that uses a 128-bit key to encrypt and decrypt data. 128-bit encryption is considered to be strong enough to resist brute-force attacks by modern computers. References: Asymmetric vs Symmetric Encryption: What are differences?, Public Key Infrastructure (PKI), Digital Signature, What is
128-bit Encryption?

The finding that should be ranked as the highest risk is that network penetration tests are not performed.
Network penetration tests are simulated cyberattacks that aim to identify and exploit the vulnerabilities and weaknesses of the network security controls, such as firewalls, routers, switches, servers, and devices.
Network penetration tests are essential for assessing the effectiveness and resilience of the network security posture, and for providing recommendations for improvement and remediation. If network penetration tests are not performed, the organization may not be aware of the existing or potential threats and risks to its network, and may not be able to prevent or respond to real cyberattacks, which can result in data breaches, service disruptions, financial losses, reputational damage, and legal or regulatory penalties. The other findings are also important, butnot as risky as the lack of network penetration tests, because they either do not directly affect the networksecurity controls, or they can be addressed by documentation or approval processes. References: CISA Review Manual (Digital Version)1, Chapter 5, Section 5.2.4

The most concerning issue associated with a data center's CCTV surveillance cameras is that the recordings are not regularly reviewed. This means that any unauthorized access, theft, vandalism, or other security incidents may go unnoticed and unreported. CCTV recordings are a valuable source of evidence and deterrence for data center security, and they should be monitored and audited periodically to ensure compliance with policies and regulations. If the recordings are not reviewed, the data center may face legal, financial, or reputational risks in case of a security breach or an audit failure.
The other options are less concerning because they do not directly affect the security of the data center. CCTV cameras are not required to be installed in break rooms, as they are not critical areas for data protection.
CCTV records can be deleted after one year, as long as they comply with the data retention policy of the organization and the applicable laws. CCTV footage does not need to be recorded 24 x 7,as long as there is sufficient coverage of the data center during operational hours and when access is granted to authorized personnel. References:
* ISACA Journal Article: Physical security of a data center1
* Data Center Security: Checklist and Best Practices | Kisi2
* Video Surveillance Best Practices | Taylored Systems