Answer:
The correct answer is A
Step-by-step explanation:
When someone represent someone else, then that person is responsible for the actions taken by him and it is the responsibility of that person to fulfill his or her obligations in correct or right way.
Under this situation, Bob (B) represents the Mary (M) and M would like to make an offer for the house, so B is responsible to write the offer and submit it. But B unable to fulfill the responsibility and terminates the relationship with M.
Therefore, No, B has not acted or behaved properly and also should have submitted the offer.