Explanation
Issue log and change log are documents that should be used to record the event where the project team has just experienced an unexpected event and implemented a work-around. An issue log is a document that tracks and records any issues or problems that arise during a project and how they are resolved. An issue log can help to monitor and control the project performance and quality and prevent any negative impacts on the project objectives and deliverables. A change log is a document that tracks and records any changes or modifications that are made to the project scope, schedule, cost, quality, or resources during a project. A change log can help to document the change request, approval, implementation, and impact of each change and ensure traceability and transparency.

In order to find the client billing rate for a particular engineer, the project manager would need to refer to the SOW (Statement of Work). The SOW is a document that outlines the work to be performed, the timeframe for completion, and the cost of the project. It also includes information about the resources involved in the project and their billing rates. References: CompTIA Project+ Study Guide Section 2.2.
The project manager would need a statement of work (SOW) to find information about the client billing rate for a particular engineer. A SOW is a document that defines the scope of work for a project or contract. It usually includes information such as deliverables, milestones, timeline, costs, payment terms, quality standards, and acceptance criteria. A SOW can help to specify what services or products will be provided by whom, when, where, how, and for how much.

A business collaboration tool is a software that enables teams to communicate, share, and create together online. A business collaboration tool can help project teams across multiple time zones to overcome the challenges of distance, time differences, and cultural diversity. A business collaboration tool can provide features such as instant messaging, video conferencing, file sharing, document editing, project management, and more. A business collaboration tool can also integrate with other applications and platforms that the project team uses. A business collaboration tool can improve the efficiency, productivity, and quality of the project team's work12. References = CompTIA Project+ Study Guide: Exam PK0-005, 3rd Edition, Chapter
4: Project Communications, p. 137; The 15 best collaboration tools for productive teams - Workable; 17 Best Business Collaboration Tools for Teams - Venngage

During the project closure phase in the waterfall methodology, it is crucial to validate the deliverables to ensure that all project requirements have been met and the project outputs are complete and satisfactory.
Additionally, reconciling the project budget is performed to ensure all financial records are accurate and reflect the actual project costs, which is essential for the formal closing of the project.
References = CompTIA Project+ Certification Study Guide (PK0-005)

The project manager should communicate the change deployment next after updating the project plan with the
newest project end date as a result of an approved change. Communicating the change deployment involves
informing all relevant parties about when and how the change will be implemented and what are the expected
outcomes and benefits. Communicating the change deployment can help to ensure alignment, readiness, and
support for the change and avoid any confusion or resistance.