Choose the correct preposition to fill in the blank in the sentence given below.

Several small business owners fell prey ________ sophisticated phishing scams during the holiday season.

The correct answer is to.

Step-by-Step Explanation:
1. Identify the Idiomatic Phrase: The sentence requires a preposition to complete the standard English idiomatic expression "fall prey to".
2. Meaning of the Phrase: "To fall prey to" means to become a victim of someone or something, or to be tricked, cheated, or harmed by something.
3. Grammatical Collocation: The verb phrase "fall prey" (or past tense "fell prey") is always followed by the preposition to when specifying the cause or source of harm/victimization.

Analysis of Options:
• to: Correct. It completes the fixed expression "fell prey to".
• of: Incorrect. While "prey of" exists as a noun phrase (e.g., "a prey of predators"), the verb construction "fall prey" strictly requires "to".
• against: Incorrect. "Against" denotes opposition or resistance and does not collocate with "fell prey".
• by: Incorrect. Although "by" is often used in passive voice agent phrases, it is grammatically incorrect after the phrase "fell prey".

Complete Sentence:
"Several small business owners fell prey to sophisticated phishing scams during the holiday season."