"Polio" is an abbreviation for Poliomyelitis, which is a very rare disease that affects the nervous system in your body.
In order to be able to answer this, we'd need to know what book it is you're reading, as well as the answer choices as the question asks "which of the following best" meaning that they want you to choose the best answer from the choices they’re giving you.
Answer:
Fantasy/Mythical creatures
Explanation:
