Step 1: Understanding the Question:
This is a standard grammar question focusing on the correct usage of prepositions.
The sentence expresses a strong dislike ("aversion") of the boy towards "bland food".
We must identify the fixed preposition that idiomatically follows the noun "aversion".
Step 2: Key Formulas and approach:
Many nouns, verbs, and adjectives in the English language take a fixed preposition.
The noun "aversion", which means a strong dislike or disinclination, is grammatically paired with a specific preposition to direct the dislike towards an object.
Step 3: Detailed Explanation:
$\bullet$ In standard English grammar, the noun "aversion" is followed by the preposition "to".
$\bullet$ We say "aversion to something" (e.g., an aversion to risk, an aversion to public speaking).
$\bullet$ The prepositions "at", "with", and "for" do not form the correct idiomatic phrase when paired with the noun "aversion".
$\bullet$ Although "aversion for" is sometimes colloquially heard, "aversion to" is the globally accepted standard in formal competitive examinations.
Step 4: Final Answer:
Thus, "to" is the correct preposition, making Option (B) the correct answer.