Critical Reasoning

I am not convinced by the explanation given in OG. Please help me convince.
Which of the following most logically completes the argument given below:-
The irradiation of food kills bacteria and thus retards spoilage. However, it also lowers the nutritional value of many foods. For example, irradiation destroys a significant percentage of whatever vit B1 a food may contain. Proponents of irradiation is no worse in this respect than cooking. However, this fact is either beside the point, or else misleading, since ________________.

(A) many of the proponents of irradiation are food distributors who gain from foods' having a longer shelf life
(B) it is clear that killing bacteria that may be present on food is not the only effect that irradiation has
(C) cooking is usually the final step in preparing food for consumption, whereas irradiation serves to ensure a longer shelf life for perishable food
(D) certain kinds f cooking are, in fact, even more destructive of vit B1 than carefully controlled irradiation is
(E) for food that is both irradiated and cooked, the reduction of vit B1 associated with either process individually is compounded

Please explain how (E) fits in the argument.