The project manager experiences difficulties working with the customer. After the project is finished，the customer states that the project was nor completed to their satisfaction. What should the project manager have done throughout the project to avoid this outcome?
A、Advise the customer that their request are being implemented at each project phase
B、Understand，evaluate, define, and manage customer expectations
C、Send the customer the technical specifications for review and approval
D、Identified and replace responsible parties from the project team