A project manager took over a project which is in the execution phase. The customer is unable to define the project’s objectives in the required  detailed level and the project team members have started complaining that continuous changes in requirements makes estimating work effort and schedule impossible. How should the project manager proceed?
A、  Tell the customer about team members’ complaints and ask for more detailed requirements.
B、   Tell the project team members the customer is not able tell the requirements at required pace.
C、   Update the high level WBS with more detailed information when it is available.
D、   Keep the project team occupied with the current assignments.