The Graph Below Is of an Index of Diversity of Arthropods

Multiple Choice

The graph below is of an index of diversity of arthropods in three different plots of a cornfield. In one of the three plots an insecticide was sprayed. Answer the questions below about this situation.
Arthropod diversity in three cornfield plots.
-When and where does it appear that the insecticide was applied?

A) in August in Plot 3
B) in July in Plot 3
C) in June in Plot 1
D) in May in Plot 1