What is the clock status if B intercepts and, prior to the interception, B commits a foul?
I think the ball will be given back to A, and the clock should start on the snap because the interception was the action that caused the clock to become stopped.
Rule 3-4-2-b-3 states:
ART. 2 . . . The clock shall start with the ready-for-play signal for other than a free kick if the clock was stopped:b. Because the ball has become dead following any foul provided in either (a) or (b)
3. The action which caused the down to end did not also cause the clock to be stopped.