The correct answer is option C. "To send his son back to the cemetery"
Explanation:
In the short story "The Monkey's Paw" by W.W. Jacobs three wishes are granted to Mr. White, but the wishes backfired and had bad consequences as a result of interfering with fate. First, Mr. White wishes for money to make the final mortgage payment for his house, but then his son got killed in a machinery accident and the firm where he worked gave him the exact same amount of money he wished for as a goodwill payment. The second wish comes from his wife that want his son back to life, but her son came back as a monster that is knocking at their door. Mr. White's final wish is not clearly stated but it is most likely that it was to send his son back to the cemetery because the knocking stops once Mr. White makes his final wish.