Which words in the sentence form the participial phrase? We found mold and mildew on many of the old books stored in the damp basement. A. We found B. on many of the old books C. mold and mildew D. stored in the damp basement

The participial phrase in this example is D - stored in the damp basement, as it is both a phrase (doesn't have a verb used with a certain person - stored is participle here, used as an adjective, not a verb) and it has this participle. In the previous options, A - we found - this is not a phrase, here verb is used as a verb, and thus it is a sentence, not a phrase. B - many of the old books - this is a noun phrase, it is about books. C - mold and mildew is an adjectival phrase. And thus, the only plausible answer here is D.