Which of the following is a key activity found in Phase 3 of the project?a.)Closed the project since the deliverables met all of the defined requirements.b.)Created a scope document and resource plan for the new rewards program.c.)Made change requests to resolve the problems with the deliverable.d.)Documented assumptions about future work.

The key activity found in Phase 3 of the project is likely to be "Made change requests to resolve the problems with the deliverable."

This is because Phase 3 of a project typically involves the execution and control phase. During this phase, the project team is carrying out the project plan and producing the deliverables. It's also the phase where any issues or changes are addressed, which often involves making change requests to resolve problems with the deliverable.

The other options listed seem to correspond to other phases of a project. For example, creating a scope document and resource plan (option b) is usually part of the planning phase (Phase 2), while closing the project (option a) is part of the closing phase (Phase 5). Documenting assumptions about future work (option d) could be part of the initiating phase (Phase 1) or planning phase (Phase 2).