The most important process to help ensure the application provides accurate calculations is quality assurance (QA), which involves verifying that the application meets the specified requirements and standards, and testing the application for functionality, performance, reliability, security, and usability. QA helps to identify and correct any defects or errors in the application before it is deployed to the production environment. Key performance indicator (KPI) monitoring, change management, and configuration management are important processes for managing and maintaining the application after it is implemented, but they do not directly ensure the accuracy of the calculationsperformed by the application. References: CISA Review Manual (Digital Version), Chapter 3: Information Systems Acquisition, Development and Implementation, Section
3.3: Practices for Quality Assurance

The most important issue for an IS auditor to consider with regard to Voice-over IP (VoIP) communications is the homogeneity of the network, because it affects the quality, security, and reliability of the VoIP service. Ahomogeneous network is one that uses a single protocol or standard for VoIP communication, such as Session Initiation Protocol (SIP) or H.32312. A homogeneous network can reduce thecomplexity, latency, and interoperability issues that may arise from using different or incompatible protocols or devices forVoIP communication12. Continuity of service, identity management, and nonrepudiation are also important issues for VoIP communications, but not as important as the homogeneity of the network. References: 1: CISA Review Manual (Digital Version), Chapter 4, Section 4.4.3 2: CISA Online Review Course, Module 4, Lesson 4

Disabling USB access for storage devices is a preventive control because it is intended to stop malware introduction before it occurs. ISACA explicitly describes disabling USB access for storage devices as a preventive control that makes it harder for users to introduce threats such as viruses into the environment.
Option C is correct because the control works in advance of the event. It prevents users from connecting removable storage that could carry malicious software or facilitate unauthorized data transfer.
Option A is incorrect because corrective controls act after an incident to restore or remediate conditions. USB blocking does not restore anything after infection.
Option B is not the best answer because although administrative policy may require the control, the specific control being described functionally prevents an unwanted event. In CISA questions, the functional type is the better classification here.
Option D is incorrect because the control is not physical; it is a logical/technical measure enforced through system configuration.
Therefore, C is the best answer because disabling USB storage access is designed to prevent malware from being introduced through physical media.
References (Official ISACA):
ISACA, Specific Controls You Can Use - disabling USB access for storage devices is described as a preventive control.
ISACA Journal, Addressing Cybersecurity Vulnerabilities - preventive controls are used to reduce exposure before compromise.

The first thing that an IS auditor should do when a follow-up audit reveals some management action plans have not been initiated is to escalate the lack of plan completion to executive management. This is because the failure to implement the agreed management action plans may indicate that the management is not taking the audit findings and recommendations seriously, or that they are accepting too much risk by not addressing the identified issues. Escalating the lack of plan completion to executive management can help to raise awareness and accountability, as well as to seek support and intervention to ensure that the management action plans are executed in a timely and effective manner12.
Confirming whether the identified risks are still valid is not the first thing to do, although it may be a useful step to reassess the current situation and the potential impact of not implementing the management action plans. However,confirming the validity of the risks does not address the root causeof why the management action plans have not been initiated, nor does it provide any assurance or remediation for the unresolved issues34.
Providing a report to the audit committee is not the first thing to do, although it may be a necessary step to communicate and document the results of the follow-up audit. However, providing a report to the audit committee does not guarantee that the management action plans will be initiated, nor does it resolve any conflicts or challenges that may prevent the management from implementing them34.
Requesting an additional action plan review to confirm the findings is not the first thing to do, although it may be a prudent step to verify and validate the accuracy and completeness of the follow-up audit. However, requesting an additional review may delay or defer the implementation of the management action plans, as well as consume more internalaudit resources and time