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?
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Premise: This special enzyme, when ingested, can kill immature caterpillars.
Ask: Why isn't it advisable to eradicate immature caterpillars?
Pre-thinking: Now, why shouldn't we try to eradicate pests that go through immature caterpillar stage?
1) Immature caterpillars are harmless or even beneficial to the crops
2) spraying this enzyme may have some downsides. The enzymes may hurt crops more than immature caterpillars do
(A) Most species of caterpillar are subject to some natural predation.--> It helps, and may even lead us to think that if caterpillars have natural predators, then killing them would be redundant.
This was not part of my pre-thinking options. Let's hold onto this one for now and see if we can find something better.
(B) Many agricultural pests do not go through a caterpillar stage. --> We are concerned with the ones that go through caterpillar stage.
(C) Many agriculturally beneficial insects go through a caterpillar stage. CORRECT-->This matches our pre-thinking. If these pests are beneficial for the crops, we shouldn't kill them.
Now, between A and C, C comes across as a much stronger option that supports not killing caterpillars.
(D) Since caterpillars of different species emerge at different times, several sprayings would be necessary.--> Doesn't touch core of the problem. Spraying enzymes regularly may or may not be a problem.
(E) Although the enzyme has been synthesized in the laboratory, no large-scale production facilities exist as yet.--> This kinda directs to the fact that 'farmer' doesn't have the enzyme to spray on his farm. But, the question focuses on why shouldn't the farmer spray, regardless of the availability of the enzyme.