A. other pesticides' chemical compositions already in wide use refers to wide usage of chemical composition whereas it should refer to wide usage of other pesticide. Also it does not connect to the rest of the sentence 'neutralizing its desired effect.

B. Does not connect to the rest of the sentence'neutralizing its desired effect..

C Correct : conveys the meaning clearly, and links with the remaining sentence 'neutralizing its desired effect.. with the correct verb (present perfect) have been neutralizing..

D. verbose. Also it is not pesticide which is neutalizing the effect but the chemical component present in other pesticides which is neutralizing the effect.

E. Pesticides are in wide usage whereas in the sentence other pesticides and their chemical compositions already in use, suggests that pesticides and their chemical compositions are in usage. So in a way it changes the intended meaning of the sentence, therefore incorrect.

imo:C

A. because other pesticides' chemical compositions already in wide use-modifier problem

Is it the wide use or chemical composition that is neutralising.

B. because of the chemical compositions of the pesticides already in wide use

same problem

C. due to other pesticides already in wide use, whose chemical compositions have been

clear and concise

D. since, due to the chemical compositions of other pesticides already in use, those pesticides have been

E. because of other pesticides and their chemical compositions already in use, which have been