Answer:
Idiom
Step-by-step explanation:
The options you were given are the following:
- allusion
- apostrophe
- hyperbole
- idiom
Idioms are phrases that don't have a literal meaning. This means that we can't conclude what a phrase means based on the meanings of words that make it up. We simply have to learn what these phrases mean.
An example of an idiom is in one ear and out the other. This doesn't mean that something enters through one and exits through the other ear. Actually, this expression refers to an instance when someone ignores, dismisses, or forgets something almost immediately after being told. In this case, Dahl's antagonist keeps forgetting Billy's name instantly after hearing it.