This is an issue with consumers’ storage practices, not with irradiation. Also, the author only claims that irradiation prevents food from spoiling before it reaches stores. He doesn’t say anything about it spoiling after it’s purchased. (A) also fails to address vitamin loss.

The author assumes that since irradiation and cooking cause the same vitamin loss, irradiation shouldn’t be rejected for nutrition reasons. But if irradiated foods are cooked, they lose twice the vitamins. And if eaten raw, they’ve already lost more vitamins than other raw food.

This may be true, but the proponent’s conclusion addresses safety and nutrition. Vitamin loss is surely included in nutrition.

This may be true, but the argument just addresses vitamin loss due to irradiation. Even if one can still take vitamin supplements, it doesn’t impact the argument that irradiation shouldn’t be rejected for nutritional reasons because it causes the same vitamin loss as cooking.

This may be true, but it doesn't address vitamin loss, nor does it impact the argument. The argument is just about whether or not there’s grounds to reject irradiation. It doesn’t matter who benefits from the food not spoiling.