The black queen (on a7) cannot legally move to c8 since queens cannot move like knights.
Remember, the black pawns are moving down the board (toward row 1) and cannot capture backwards.
The knight on f6 cannot legally move to c8.
If the queen were to take the rook on c8, the black rook on g8 would not be able to capture the queen since the black king is in the way.
The bishop on h3 would be able to take the white queen if it were to capture the rook on c8.
Since white’s pawn on c3 has already taken the black bishop on d4 (after it takes white’s knight), there is no piece on c3 anymore. Technically black’s knight on b5 can move to c3 (notation: Nc3), but it can’t take anything on c3.
Black’s bishop doesn’t exist anymore because after it took white’s knight on c4, it was taken by white’s pawn on c3.
Black doesn’t have a pawn on the e file that would be able to take white’s pawn on d4.
Since white’s pawn on c3 has taken the black bishop on d4 (after it takes white’s knight), the c file is clear and black’s rook can take white’s rook on c1.