18.   While all states face similar industrial waste problems, the predominating industries and regulatory environment of the states obviously determines the types and amounts of waste produced, as well as the cost of disposal.

(A) all states face similar industrial waste problems, the predominating industries and regulatory environment of the states obviously determines

(B) each state faces a similar industrial waste problem, their predominant industries and regulatory environment obviously determine

(C) all states face a similar industrial waste problem, their predominating industries and regulatory environment obviously determines

(D) each state faces similar industrial waste problems, the predominant industries and regulatory environment of each state obviously determines（E）

(E) all states face similar industrial waste problems, the predominant industries and the regulatory environment of each state obviously determine

i think d is a better choice. but the answer is e, can anyone explain?

I think both D and E are totally correct.And the answer is E, what's wrong is D?

thanks !!!!!!1