It isn't just a question of answering THIS check. If Black wants to win, he must find a way to escape from the White Queen's REPEATED checks.
So after your 1. ... Kb7 and White plays 2. Qd7+ how are you planning to prevent White from getting a draw by just checking you back-and-forth, back-and-forth?
By playing 1. ... Kb5 instead, you are heading your King towards the a3 square, where he will find a place to hide, shielded from checks by his other pieces.
In this position, Qd8+, and my king should move away from check and no other pieces can move. In this case, I played Kb7, knowing that it is the best move to move away from check, without thinking other ideas about the queen giving checks. Unfortunately, chess.com determined that Kb7 is incorrect, and the only solution is Kb5. IDK why this actually happened about the king, whose responsibility is to remove the check, because there are many other possible options to move away from check.
Do anyone agrees if Kb7 is another possible solution in this case, as well as Kb5? Just LMK with your general ideas and explanations. The first one to comment below will receive a random daily challenge!