Answer:
The correct answer is:
Whether any maize-eating insects compete with monarch caterpillars for the leaves of milkweed plants growing near maize fields (E)
Step-by-step explanation:
Since the argument has to do with the elimination of caterpillars of monarch butterflies by the insecticidal property genetically modified strains of maize, in order for the argument to hold valid, every other factor that could result in similar effect of the death of carterpillars of monarch butterflies has to be ruled out. one such factor is competition; when another species struggle for limited available nutrition with the carterpillers which can result in their death, and can easily be confused as the effect of the insecticidal property of the modified maize strain.