Answer: The revision that clarifies the confusing pronoun in this sentence is "Coach Perry told him he had previously coached basketball when Tyler was on the swim team".
Explanation: The confusing pronoun in the sentence provided is the "he" that comes after "when" since the reader cannot possibly know if "he" refers to "Coach Perry" or "Tyler". The only sentence that clarifies this confusing pronoun is the second one ("Coach Perry told him he had previously coached basketball when Tyler was on the swim team") as "he" has been replaced with the noun "Tyler" and, unlike what happens in the first and third revisions, the meaning of the sentence has not been changed. The fourth revision does not clarify the confusing pronoun either because "Coach Perry" has been omitted.
