Separately, as "Human" or "Man".
I have already encountered this problem on the last riddle of the Sphinx. Where the answer was "Riddle", but she didn't accept it either. But since it was already the last stage with her and the game was not fully released then, I just gave up on it, and decided to wait for the full release of the game. And the other day, literally, I remembered about this game, bought it in Steam, and again faced this problem, but only now on its very first riddle.
And it's sad, because the game is really very good. But it's the fact that for some reason I don't understand, I can't move forward with the storyline of the Sphinx now(