My third party supplier doesn't meet deadlines. This person is the friend of a senior manager and ignores me as the project manager. How should I deal with this?

A. Ask the senior mana~~er to talk to the supplier about attitude.

B. Construct a better procurement process for next time.

C. Warn your project team that this supplier is hostile so they can each prepare to be confrontational.

D. Ask to be included the next time the senior manager and the supplier play golf.