Anair-gapped (C)system is completely isolated from unsecured networks (like the internet) and other systems, preventing any form of remote access. This is often used in highly sensitive environments such as military, nuclear, or critical infrastructure systems.
This is mentioned underDomain 3.4: Given a scenario, apply cybersecurity resilience conceptsin the CompTIA Security+ SY0-701 Exam Objectives, specifically under"Isolation (e.g., air-gapped)".

After completing a vulnerability assessment and remediating the identified vulnerabilities, the next step is to rescan the network to verify that the vulnerabilities have been successfully fixed and no new vulnerabilities have been introduced. A vulnerability assessment is a process of identifying and evaluating the weaknesses and exposures in a network, system, or application that could be exploited by attackers. A vulnerability assessment typically involves using automated tools, such as scanners, to scan the network and generate a report of the findings. The report may include information such as the severity, impact, and remediation of the vulnerabilities. The operations team is responsible for applying the appropriate patches, updates, or configurations to address the vulnerabilities and reduce the risk to the network. A rescan is necessary to confirm that the remediation actions have been effective and that the network is secure.
Conducting an audit, initiating a penetration test, or submitting a report are not the next steps after completing a vulnerability assessment and remediating the vulnerabilities. An audit is a process of reviewing and verifying the compliance of the network with the established policies, standards, and regulations. An audit may be performed by internal or external auditors, and it may use the results of the vulnerability assessment as part of the evidence. However, an audit is not a mandatory step after a vulnerability assessment, and it does not validate the effectiveness of the remediation actions.
A penetration test is a process of simulating a real-world attack on the network to test the security defenses and identify any gaps or weaknesses. A penetration test may use the results of the vulnerability assessment as a starting point, but it goes beyond scanning and involves exploiting the vulnerabilities to gain access or cause damage. A penetration test may be performed after a vulnerability assessment, but only with the proper authorization, scope, and rules of engagement. A penetration test is not a substitute for a rescan, as it does not verify that the vulnerabilities have been fixed.
Submitting a report is a step that is done after the vulnerability assessment, but before the remediation. The report is a document that summarizes the findings and recommendations of the vulnerability assessment, and it is used to communicate the results to the stakeholders and the operations team. The report may also include a follow-up plan and a timeline for the remediation actions. However, submitting a report is not the final step after the remediation, as it does not confirm that the network is secure.
Reference = CompTIA Security+ SY0-701 Certification Study Guide, page 372-375; Professor Messer's CompTIA SY0-701 Security+ Training Course, video 4.1 - Vulnerability Scanning, 0:00 - 8:00.

The best answer is A. Data masking.
When production data is copied into a UAT (User Acceptance Testing) environment, sensitive information should be protected so that testers cannot view real confidential values such as personal data, account numbers, or other regulated information. Data masking replaces sensitive data with realistic but fictional or hidden values while preserving the format and usability of the data for testing.
This makes it ideal for non-production environments where the application still needs data that looks real, but the testing team should not be able to see actual sensitive information.
Why the other options are incorrect:
B). Data tokenizationTokenization replaces sensitive values with tokens, but it is more commonly used to protect data in operational processing systems, such as payment environments. It is not the best fit here compared with masking for UAT visibility concerns.
C). Data obfuscationObfuscation is a broader term and can mean making data harder to understand, but data masking is the more precise and standard control for protecting test data from being viewed.
D). Data encryptionEncryption protects data at rest or in transit, but once authorized testers access and use the UAT system, the application may decrypt and display the data. That does not solve the problem of testers viewing sensitive values.
From a Security+ perspective, when moving production data into development, test, or UAT environments, the preferred control to prevent exposure of real sensitive data is data masking.

The correct answer is Acquisition process because supply chain compromise risks originate before systems ever enter the organization's environment. Within the Security+ SY0-701 objectives, supply chain risk management is a core element of security governance and third-party risk oversight. Reviewing the acquisition process allows an organization to evaluate how vendors are selected, how hardware integrity is validated, and what security assurances are required before purchase and delivery.
The acquisition process includes vendor due diligence, contract requirements, sourcing controls, and verification steps that ensure hardware has not been tampered with, preloaded with malicious firmware, or altered during manufacturing or transit. The SY0-701 study guide emphasizes that organizations must assess supplier trustworthiness, require secure delivery practices, and define security expectations in contracts to reduce the risk of compromised components entering the environment. If the acquisition process is weak, downstream controls become reactive rather than preventive.
Option A, sanitization procedure, applies to data destruction and system disposal, not newly acquired servers. Option C, change management, governs how modifications are introduced into existing systems and does not address risks introduced during procurement. Option D, asset tracking, helps maintain inventory visibility once assets are received but does not prevent compromised hardware from being introduced in the first place.
By reviewing and strengthening the acquisition process first, the company can implement preventive controls such as approved vendor lists, chain-of-custody requirements, hardware integrity checks, and acceptance testing. These measures align with SY0-701 principles of reducing risk at the earliest possible stage and enforcing accountability across third-party relationships.
In summary, supply chain compromise is best mitigated by addressing risks at procurement. The acquisition process is the foundational control point where organizations can limit exposure before servers are deployed into production environments.

Detailed
Baseline enforcement ensures that all systems adhere to predefined security configurations, such as approved OS versions and patch levels, improving compliance and reducing vulnerabilities. Reference: CompTIA Security+ SY0-701 Study Guide, Domain 4: Security Operations, Section: "System Baselines and Monitoring".