Carbon dioxide fire suppression systems need to be combined with an automatic switch to shut down the electricity supply in the event of activation. This is because carbon dioxide displaces oxygen in the air and can create a suffocation hazard for people in the protected area. Therefore, it is essential to cut off the power source before releasing carbon dioxide to avoid electrical shocks and sparks that could ignite the fire again.
Carbon dioxide systems are typically used for total flooding applications in spaces that are not habitable, such as server rooms or data centers.

Impact assessment is an activity that occurs during the issues management process for a system development project. Issues management is a process of identifying, analyzing, resolving, and monitoring issues that may affect the project scope, schedule, budget, or quality. Impact assessment is a technique of evaluating the severity and priority of an issue, as well as its implications for the project objectives and deliverables. The other options are not activities that occur during the issues management process, but rather related to other processes such as contingency planning, configuration management, or help desk management. References:
CISA Review Manual (Digital Version), Chapter 4, Section 4.3.31
CISA Review Questions, Answers and Explanations Database, Question ID 217

The main risk associated with adding a new system functionality during the development phase without following a project change management process is that the new functionality may not meet requirements (option B). This is because:
A project change management process is a set of procedures that defines how changes to the project scope, schedule, budget, quality, or resources are requested, evaluated, approved, implemented, and controlled12.
A project change management process helps to ensure that the changes are aligned with the project objectives, stakeholders' expectations, and business needs12.
Adding a new system functionality during the development phase without following a project change management process can introduce risks such as:
The added functionality has not been documented (option A), which can lead to confusion, inconsistency, errors, and rework3.
The project may fail to meet the established deadline (option C), which can result in delays, penalties, and customer dissatisfaction3.
The project may go over budget (option D), which can cause cost overruns, financial losses, and reduced profitability3.
However, the main risk is that the new functionality may not meet requirements (option B), which can have serious consequences such as:
The new functionality may not be compatible with the existing system or other components3.
The new functionality may not be tested or verified for quality, performance, security, or usability3.
The new functionality may not deliver the expected value or benefits to the users or customers3.
The new functionality may not comply with the regulatory or contractual obligations3.
The new functionality may cause dissatisfaction, complaints, or litigation from the stakeholders3.
Therefore, the main risk associated with adding a new system functionality during the development phase without following a project change management process is that the new functionality may not meet requirements (option B), as this can jeopardize the success and acceptance of the project.
References: 1: How to Make a Change Management Plan (Templates Included) - ProjectManager 2: What Is Change Management? Process and Models Explained - ProjectManager 3: 8 Steps for an Effective Change Management Process - Smartsheet

Outsourcing the audit to independent and qualified resources is the best course of action for the IS audit manager who was temporarily tasked with supervising a project manager assigned to the organization's payroll application upgrade. This is because the IS audit manager has a potential conflict of interest and a threat to objectivity and independence, which are essential principles and standards for IS auditors.
According to the ISACA Code of Professional Ethics, IS auditors should maintain objectivity and independence in their professional judgment and avoid any situations that may impair or be presumed to impair their objectivity or independence1. Objectivity is the mental attitude of an IS auditor that allows them to perform their work honestly, impartially, and with integrity, while independence is the freedom from conditions that threaten the ability of an IS auditor to carry out their work in an unbiased manner2.
The IS audit manager who was involved in supervising the payroll application upgrade project may have a self-review threat, which is the risk that an IS auditor will not appropriately evaluate the results of a previous judgment made or service performed by them or their subordinates3. The IS audit manager may also have a familiarity threat, which is the risk that an IS auditor will be influenced by a close relationship with someone involved in the project or by their own personal interests4. These threats may compromise the IS audit manager's objectivity and independence and affect the quality and credibility of the audit.
Therefore, the IS audit manager should disclose their involvement in the project to their senior management and the audit committee and decline to perform or manage the audit. The IS audit manager should also recommend outsourcing the audit to independent and qualified resources who have no connection or interest in the project and who have the necessary skills and experience to conduct a reliable and effective audit.
The other options are not the best course of action for the IS audit manager.
Transferring the assignment to a different audit manager despite lack of IT project management experience is not the best course of action because it may result in a low-quality audit that does not meet the expectations and standards of the stakeholders. IT project management experience is essential for auditing an IT project, as it requires knowledge of project management methodologies, tools, techniques, risks, and best practices. An audit manager who lacks IT project management experience may not be able to plan, execute, report, and follow up on the audit effectively and efficiently.
Managing the audit since there is no one else with the appropriate experience is not the best course of action because it violates the ethical principles and standards of objectivity and independence for IS auditors.
Managing the audit would create a conflict of interest and a threat to objectivity and independence for the IS audit manager, as they would be reviewing their own work or that of their subordinate. Managing the audit would also undermine the credibility and reliability of the audit results and recommendations, as they may be biased or influenced by personal or professional relationships or interests.
Having a senior IS auditor manage the project with the IS audit manager performing final review is not the best course of action because it still involves the IS audit manager in the audit process, which poses a conflict of interest and a threat to objectivity and independence. Performing final review would require the IS audit manager to evaluate and approve the work done by the senior IS auditor, which may be affected by their previous involvement in or knowledge of the project. Performing final review would also expose theIS audit manager to undue pressure or influence from management or other stakeholders who may have expectations or preferences regarding the audit outcome.