I believe there is a problem with the answer that problems C and D are trying to extract.

If the company that drops out has no chance of success, then the probabilities of success for your company does NOT change. This is a classic Monte Hall problem. The company that drops out is the door with the goat. All the other companies are the other doors. Their chance increase...your chances do not.


Of course, your chance do go up if the company that dropped out still had some chances left