Identify the word or words the best describes the underlined(in parentheses) word for the question

Question

(Comparing the two essays), it is obvious that one relied on more thorough research.

A.prepositional phrase
B.participial phrase
C.gerund phrase
D.infinitive phrase

I think the answer is C. Thanks for the help :)

Answer 1

Gerund phrases are used as nouns. This phrase is used as an adjective.

Does this help clarify the question?

Answer 2

That makes the answer B, then?

Answer 3

Right.

Answer 4

Thanks :)

Answer 5

You're welcome.