If she answered incorrectly, then she should not come back and bother him any more. Then he could marry the one he loved.

禅师说这个鬼无所不知，知道许多事情，不过也许有些事情她不知道，如果她答错了的话，那就得答应不再回来打扰他，让他和心爱的人结婚。