After contract sign-off, a project manager learns that the vendor has a reputation of not delivering according to the contract. To ensure the vendor's compliance, what should the project manager do?


A. Cancel the current contract and select another vendor.
B. Insist on a firm fixed price (FFP) contract with the vendor.
C. Conduct a make-or-buy analysis to verify vendor reliability.
D. Perform periodic inspections of the vendor's work and progress.