The answer is:
C. The Sea of Faith / Was once, too, at the full, and round earth’s shore / Lay like the folds of a bright girdle furled
A simile is a figure of speech in which there is an explicit comparison of two different things. It is an obvious metaphor that uses words such as like, as, so, and than, and verbs similar to resemble.
In the excerpt from the poem "Dover Beach," the author Matthew Arnold uses the phrase "Sea of faith" to refer to religion, and describes it as a beautiful belt rolled around the world: "like the folds of a bright girdle furled."