This riddle asks: what has to be answered but never asks a question? At first, it sounds like it must be a person or something capable of speaking, but the trick is to think about something we commonly say we ‘answer’ even though it never actually asks anything.
The answer is a telephone. When a phone rings, we say that we answer it. The phone itself is not asking a question; it is simply signaling that someone is calling.
That is what makes the riddle work. The word ‘answer’ usually makes us think of responding to a question, but it can also mean picking up a call. Once you notice that second meaning, the clue becomes much easier. Simple wordplay riddles like this are effective because they use familiar language in an unexpected way.
