Or HaChaim on Deuteronomy 25:9/אור החיים על דברים כ״ה:ט׳

1 וענתה ואמרה ככה יעשה לאיש, "and she will say in reply: "so shall be done to any man, etc." The reason the Torah employs the term עניה, "reply," is because it is in answer to her brother-in-law who had refused to marry her.