我的几道LSAT逻辑8

renaversace

Mark: Plastic-foam cups, which contain environmentally harmful chlorofluorocarbons, should no longer be used; paper cups are preferable. Styrene, a carcinogenic by-product, is generated in foam production, and foam cups, once used, persist indefinitely in the environment.
Tina: You overlook the environmental effects of paper cups. A study done 5 years ago showed that making paper for their production burned more petroleum than was used for foam cups and used 12 times as much steam, 36 times as much electricity, and twice as much cooking water. Because paper cups weigh more, their transportation takes more energy. Paper mills produce water pollution, and when the cups decay they produce methane, a gas that contributes to harmful global warming. So they are a worse choice.
22. To decide the issue between Mark and Tina, it would first be most important to decide
(A) how soon each of the kinds of harm cited by Mark and Tina would be likely to be at its maximum level
(B) whether members of some societies use, on average, more disposable goods than do members of other societies
(C) whether it is necessary to seek a third alternative that has none of the negative consequences cited with respect to the two products
(D) how much of the chains of causation involved in the production, marketing, and disposal of the products should be considered in analyzing their environmental impact
(E) whether paper and foam cups, in their most popular sizes, hold the same quantities of liquid
为什么不能选C呢？