Black can either play Nc5 or b4, which block the bishop from checking. The king cannot take white’s rook on f8 because the bishop would still be attacking that square. And, the king cannot move to f7 or e8 because of white’s rook.
The only move white can make is Bd4, taking the knight that’s putting white’s king in check. White’s king can’t move anywhere on the 1 row because of black’s rook; d2 because of black’s king; c3 or b2 because of black’s pawns (remember, we’re viewing the board from black’s side); or b3 because of black’s knight.