49.Black to move

In the position above it seem like Black is in difficult situation without a Queen.the question is

a)If possible What do you think the best continuation for Black to prevent from losing?


Thanks again to Eugene for solving problem 48 and yes 1.Bc7 is the only move that give white an advantage by material Rxc7 2.Qe5 Kf8 3.Qxc7 Bd6 4.Qd8+ Be8 5.Rh3 with accurate play there's nothing can stop white from winning.