PMP Certification Monitoring and Controlling Test 1

To ensure that every part of a project is not reworked, a project manager establishes a quality control task for each deliverable. However, the team believes that the additional review tasks are a waste of time. While they initially follow the quality control schedule, they stop shortly thereafter. Five weeks after the release of one of the deliverables, the client informs the project manager that there are some flaws that render the deliverable useless. The client wants the problem corrected at no additional cost, and sets a deadline of three days.
What should the project manager do first?