Use the Following Information When Answering the Corresponding Question(s)

Use the following information when answering the corresponding question(s) .
Some plants have continually produced secondary defense compounds.Other plants are induced to form secondary defense compounds when they are injured.Corn seedling leaves that are chewed on by the caterpillars of a type of cutworm moth emit immediate volatile chemicals (LOX products) ,and after 6 hours large amounts of terpenoid compounds are released into the air.The terpenoids are released not only from the leaf being chewed,but from all leaves of the plant.The terpenoid compounds attract a parasitoid wasp female that lays her eggs on the caterpillar.When the wasp larvae hatch,they eat and kill the moth caterpillar.(T.C.J.Turlings,J.H.Loughrin,P.J.McCall,U.S.R.Rose,W.J.Lewis,and J.H.Tumlinson.1995.How caterpillar-damaged plants protect themselves by attracting parasitic wasps.Proceedings of the National Academy of Sciences 92:4169-74. )
-Refer to the paragraph on how caterpillar-damaged plants protect themselves by attracting parasitic wasps.How could you test the hypothesis that caterpillar saliva and a wound are both necessary to attract the parasitoid wasps?

A) Slash the corn leaves with a razor blade.
B) Put caterpillar saliva on a leaf wound.
C) Put caterpillar saliva on an intact leaf.
D) All of the above actions are necessary for testing the hypothesis.