The Asian Longhorned Beetle Kills Trees by Burrowing Within the Trunk

Multiple Choice

The Asian longhorned beetle kills trees by burrowing within the trunk and branches and disrupting the sap flow.This beetle favors hardwood trees,such as maple,elm,and ash.A new pesticide will be be tested in a major metropolitan city.A statistician designs an experiment for 200 mature maple trees and randomly assigns half of the trees to receive this new pesticide,and the rest of the trees receive a control treatment.
Is there any obvious way to improve this experiment to evaluate the effectiveness of this new pesticide?

A) Yes,stratifying must be used.
B) Yes,blocking must be used.
C) No,basic variations have been accounted for.
D) Yes,matching must be used.
E) Yes,a placebo is missing.