The security strategy that you would likely suggest is to adopt a Continual/Adaptive Security Strategy involving ongoing prediction, prevention, detection, and response actions to ensure comprehensive computer network defense. This strategy is based on the concept of continuous monitoring and improvement of the security posture of an organization, using a feedback loop that integrates various security activities and technologies. A Continual/Adaptive Security Strategy aims to proactively identify and mitigate emerging threats, vulnerabilities, and risks, as well as to respond effectively and efficiently to security incidents and breaches. A Continual/Adaptive Security Strategy can help enhance the organization's security stance by providing the following benefits12:
* It can reduce the attack surface and the exposure time of the organization's network infrastructure, by applying timely patches, updates, and configurations, as well as by implementing security controls and policies.
* It can increase the visibility and awareness of the organization's network activity and behavior, by collecting, analyzing, and correlating data from various sources, such as logs, sensors, alerts, and reports.
* It can improve the detection and prevention capabilities of the organization, by using advanced tools and techniques, such as artificial intelligence, machine learning, threat intelligence, and behavioral analytics, to identify and block malicious or anomalous patterns and indicators.
* It can enhance the response and recovery processes of the organization, by using automated and orchestrated actions, such as isolation, quarantine, remediation, and restoration, to contain and resolve security incidents and breaches, as well as by conducting lessons learned and root cause analysis to prevent recurrence.
The other options are not as appropriate as option C for the following reasons:
* A. Develop an in-depth Risk Management process, involving identification, assessment, treatment, tracking, and review of risks to control the potential effects on the organization: This option is not sufficient because risk management is only one aspect of a comprehensive security strategy, and it does not address the dynamic and evolving nature of cyber threats and vulnerabilities. Risk management is a process of identifying, analyzing, evaluating, and treating the risks that may affect the organization's objectives and operations, as well as monitoring and reviewing the effectiveness of the risk treatment measures3. Risk management can help the organization prioritize and allocate resources for security, but it cannot guarantee the prevention or detection of security incidents and breaches, nor the response and recovery from them.
* B. Establish a Defense-in-Depth strategy, incorporating multiple layers of security measures to increase the complexity and decrease the likelihood of a successful attack: This option is not optimal because defense-in-depth is a traditional and static approach to security, and it may not be able to cope with the sophisticated and persistent attacks that exploit unknown or zero-day vulnerabilities. Defense-in-depth is a strategy of implementing multiple and diverse security controls and mechanisms at different layers of the organization's network infrastructure, such as perimeter, network, endpoint, application, and data, to provide redundancy and resilience against attacks4. Defense-in-depth can help the organization protect its assets and systems from unauthorized access or damage, but it cannot ensure the timely detection and response to security incidents and breaches, nor the continuous improvement of the security posture.
* D. Implement an Information Assurance (IA) policy focusing on ensuring the integrity, availability, confidentiality, and authenticity of information systems: This option is not comprehensive because information assurance is a subset of cybersecurity, and it does not cover all the aspects of a holistic security strategy. Information assurance is a discipline of managing the risks associated with the use, processing, storage, and transmission of information and data, and ensuring the protection of the information and data from unauthorized access, use, disclosure, modification, or destruction5.
Information assurance can help the organization safeguard its information and data from compromise or loss, but it does not address the prevention, detection, and response to security incidents and breaches, nor the adaptation and innovation of the security technologies and processes.
References:
* 1: Continual/Adaptive Security Strategy - an overview | ScienceDirect Topics
* 2: Continual Adaptive Security: A New Approach to Cybersecurity | SecurityWeek.Com
* 3: Risk Management - an overview | ScienceDirect Topics
* 4: Defense in Depth - an overview | ScienceDirect Topics
* 5: Information Assurance - an overview | ScienceDirect Topics

Scammers often impersonate legitimate organizations using free email services like @yahoo.com. "Yahoo Bank" is not a legitimate institution, and a real financial entity would use an official domain (e.g.,
@yahoobank.com). This is a textbook phishing/smishing attempt.
Reference - CEH v13 Official Study Guide:
Module 9: Social Engineering
Quote:
"Attackers often use free email services and impersonate authority figures to trick users. Always verify the sender's domain and context." Incorrect Options:
B: Irrelevant-legitimate people may be unknown too.
C: Responding increases risk.
D: It is not from a verified organization.

Rootkits can deeply infect and compromise a system's kernel, making them very difficult to detect or remove fully. Even advanced antivirus solutions may miss them.
The most secure and recommended response is:
* Completely wipe the compromised system.
* Reinstall the OS from known good (clean) media.
* Apply all patches and updates.
From CEH v13 Official Courseware:
* Module 6: Malware Threats # Rootkit Handling
Incorrect Options:
* A: Copying files might transfer infected components.
* B: Trap and trace is investigative, not remedial.
* C: Deleting files may not fully remove the rootkit.
* D: Backups might be infected if taken post-compromise.
Reference:CEH v13 Study Guide - Module 6: Rootkit Detection and RecoverySANS Incident Handling Handbook

MX (Mail Exchange) records in DNS define the mail servers responsible for receiving email for a domain.
Each MX record has a priority value.
Important concept:
* A lower number indicates a higher priority.
* Email servers attempt delivery to the mail server with the lowest priority first.
For example:
If MX records are:
* 10 mail1.example.com
* 20 mail2.example.com
Then mail1 will be tried first. If it fails, mail2 will be used.
So the statement "MX record priority increases as the number increases" is false.
Reference:CEH v13 Study Guide - Module 3: DNS Records # MX Record Priority ExplanationRFC 974 - Mail Routing and the Domain System

Vulnerability-Management Life Cycle The vulnerability management life cycle is an important process that helps identify and remediate security weaknesses before they can be exploited. 4.Remediation - applying fixes on vulnerable systems in order to reduce the impact and severity of vulnerabilities. (P.515/499)