Last week local shrimpers held a news conference to take some credit for the resurgence of

the rare Kemp’s ridley turtle, saying that their compliance with laws requiring that turtle-excluder

devices be on shrimp nets protect adult sea turtles.

(A) requiring that turtle-excluder devices be on shrimp nets protect

(B) requiring turtle-excluder devices on shrimp nets is protecting

(C) that require turtle-excluder devices on shrimp nets protect

(D) to require turtle-excluder devices on shrimp nets are protecting

(E) to require turtle-excluder devices on shrimp nets is protecting
对于E选项的解释：to do表示目的，而is protecting是成效。两者互相违背。这样理解可以吗？
其实，manhattan里面提到过to do也可以作modifier的，为什么这里强调内容就用doing呢？