NOTE: This is a multi$-$part question. Once an answer is submitted, you will be unable to return to this part. An explorer is captured by a group of cannibals. There are two types of cannibals$-$those who always tell the truth and those who always lie. The cannibals will barbecue the explorer unless he can determine whether a particular cannibal always lies or always tells the truth. He is allowed to ask the cannibal exactly one question.

Why does the question "Are you a liar?" not work?