Would it not be a coral reaf? Home to hundreds of fish and under water plants?
Im guessing its B, Because it just makes more sense! I went in there and read it aloud using both words (A and B) B made more sense. With an object being measured, such as a lemon, to make a quart of lemon juice, Id say you'd use the word number. Amount is not a word used for an object or measurement.
