She has a strong aversion ____ spicy food.

Concept

In English, many nouns conventionally govern a particular preposition when they introduce a complement. This fixed noun–preposition pairing is a collocation, so the choice follows established usage rather than a word-for-word meaning.

Application

The noun “aversion” means a strong dislike. Standard usage gives the pattern “aversion to somebody or something,” so the sentence becomes “She has a strong aversion to spicy food.”

Contrast

• “For” commonly marks purpose, benefit, duration, or an intended recipient; those are different relations from this noun–complement pattern.

• “About” commonly introduces a topic or an approximate quantity; it does not supply the established collocation used here.

• “Against” commonly marks opposition, contact, or protection; it is not the conventional complement marker after “aversion.”

Result

Therefore, the required preposition is “to.”