请教OG-134

134. Caterpillars of all species produce an identical hormone called "juvenile hormone" that
maintains feeding behavior. Only when a caterpillar has grown to the right size for pupation
to take place does a special enzyme halt the production of juvenile hormone. This enzyme
can be synthesized and will, on being ingested by immature caterpillars, kill them by
stopping them from feeding.
Which of the following, if true, most strongly supports the view that it would not be advisable
to try to eradicate agricultural pests that go through a caterpillar stage by spraying
croplands with the enzyme mentioned above?
(A) Most species of caterpillar are subject to some natural predation.
(B) Many agricultural pests do not go through a caterpillar stage.
(C) Many agriculturally beneficial insects go through a caterpillar stage.
(D) Since caterpillars of different species emerge at different times, several sprayings
would be necessary.
(E) Although the enzyme has been synthesized in the laboratory, no large-scale production facilities exist as yet.

我觉得这道题目B比C更加有效而直接的weaken了结论啊。严格的说，甚至可以把C当作无关答案。请大虾们指教。