Gmatprep comparision

[veekay]

Why E is correct. As is used for clause. Here as is used to compare with noun
Letr me know your thoughts

[optimisticsam]

I think this is because their teeth do not act similar to teeth (which I think D implies). They actually are used as teeth.

Just my opinion.

Correct?

[Preetics]

I think it is because option D is more wordy. There is no reason to have " do". It is implied that there is a "do" after the sentence in option E and thus is more concise