Explanation
When implementing an IT infrastructure change that takes risks into consideration, the project manager should develop a rollback plan. A rollback plan is a contingency plan that outlines the steps that need to be taken in case the change does not work as expected. It includes a plan to roll back the changes and restore the system to its previous state. References: CompTIA Project+ Study Guide Section 3.3.
The project manager should develop a rollback plan when implementing an IT infrastructure change that takes risks into consideration. A rollback plan is a contingency plan that describes how to revert back to the previous state of the system in case of a failure or disruption during the change implementation. A rollback plan can help to minimize the impact of the change on the system performance and availability and ensure business continuity and data integrity.

Avoiding is a conflict resolution technique that involves postponing or withdrawing from a conflict situation.
The project manager is using this technique by taking a break and continuing the meeting on another day, hoping that the conflict will resolve itself or become less important over time. This technique may be appropriate when the conflict is trivial, the potential damage is greater than the benefits, or more information is needed before making a decision. References = CompTIA Project+ Study Guide: Exam PK0-005, 3rd Edition, Chapter 10: Executing and Closing Projects, page 287; [CompTIA Project+ Certification Exam Objectives], Domain 3: Project Execution, Objective 3.2: Given a scenario, apply appropriate conflict resolution techniques.

The project manager can use the survey results as an input for performance feedback for the project team members. Performance feedback is a process of providing constructive and timely information on the performance of individuals or teams in relation to project goals and expectations. Performance feedback can help to motivate, improve, and recognize project team members345 The survey results can be used as an input for performance feedback. Performance feedback involves analyzing and evaluating the performance of the project team and project management against the project plan, including identifying areas for improvement. The survey results can help identify these areas for improvement and provide feedback to the project team on their performance. References: CompTIA Project+ Study Guide Section 4.1.1

Assess the impact of the request and create a change request. The project manager should assess the impact of the request and create a change request in response to the stakeholder asking to add mobile device functionality to a project that is on track to be completed under budget and ahead of schedule. A change request is a document that formally proposes and records a modification or addition to some aspect of a project, such as scope, schedule, cost, quality, or resources. A change request can help to communicate and justify the need and rationale for the change and its implications on the project objectives and deliverables. A change request also helps to initiate the change control process, which involves reviewing, approving, implementing, and monitoring the change12

The project manager should have a meeting with the project sponsor and main stakeholders first after discovering that some of the legal requirements have not been addressed during the project concept preparation. The project sponsor and main stakeholders are the key decision-makers and influencers of the project. They have the authority and responsibility to approve or reject any changes to the project scope, budget, or schedule. Having a meeting with them can help to communicate the issue, assess the impact, explore alternatives, and seek guidance on how to proceed with the project34