Help!SAT Writting

The hummingbird may appear to be a delicate creature but its body is proportionately (more muscular than any bird)
A. Same
B. more muscular than the other bird
C. more muscular than that of any bird
D.the most muscular compared to that of other birds
E.the most muscular of any other bird

I thought the answer was D. Why is the answer C ? thanks in advance

D is redundant. Words like “more” and “most” are comparative by nature. Using the word “compared” adds no real content to the sentence.

C is better than A, B, and E because the thing being compared is the hummingbird’s body (not the bird) and “that” refers to any other bird’s “body.” So the same kinds of things are being compared. The others are wrong because they try to compare a body to a bird.

Actually, I think D is wrong for a different reason. D states “the most muscular compared to that of other birds”. Instead of “that”, “those” should be used. Multiple birds cannot have one body. They must have multiple bodies. Only the usage of “those” reflects that fact in this sentence.

Meanwhile, for answer C, “that” is used correctly. “Any bird” is singular so the singular “that” correctly refers to a single body.

You’re both right about (D)–it’s wrong for two different reasons, as is often the case.