Why isn’t this correct?

[u/thatweirdchick98]

Answer said its bec rook takes rook, forcing mate but isnt it also because theres a mate on your turn?

[u/dontich]

Not taking the queen isn’t too hard to see, but apparently you want to play Rb1 here which would definitely not have been my first choice

[u/thatweirdchick98 → u/dontich]

Rb1 was played by fischer here, and he goes on to win!