Which type of elaboration allows a project management team to manage at a greater level of detail as the project evolves?

This process is concerned with determining the engagement levels of the stakeholders, understanding their needs and interests, and understanding how they might impact the project or how the project may impact them:

Which type of contract gives both the seller and the buyer flexibility to deviate from performance with financial incentives?

A project manager is reporting the final status of the closed contract to the stakeholders. Which form of communication is appropriate?

During the implementation phase of a project, functional managers are adding new requirements, which may impact cost and schedule baselines. The project manager notices that some of the team members are communicating with their managers directly to fulfill their requests.
This will lead the project to go beyond the agreed baselines.
How should the project manager handle this situation?