Which words in the sentence make up the adverb phrase?

The young volunteers planted several new flowers along the fence.

a. planted several

b. the young volunteers

c. along the fence

d. new flowers

Hello, the correct answer is - C, "along the fence". A cannot be correct because it is not an adverb phrase, "planted" is a verb, and "several" is an adjective. B is also not correct, because that example shows us the subject, not adverb. D is not correct as it is object. So the only option left is C.