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.
C - A poignant description of the strengths and faults of America.
Explanation:
The author uses the words and phrases 'her vigor', 'might and granite wonders', 'pricess treasures' to describe the strengths of America and 'bread of bitterness', 'cultured hell', 'darkly I gaze a head' to describe the faults.
