关于一道PREP题的疑问

lxw19

From 1978 to 1988, beverage containers accounted for a steadily decreasing percentage of the total weight of household garbage in the United States.  The increasingly widespread practice of recycling aluminum and glass was responsible for most of this decline.  However, although aluminum recycling was more widely practiced in this period than glass recycling, it was found that the weight of glass bottles in household garbage declined by a greater percentage than the weight of aluminum cans.

Which of the following, if true of the United States in the period 1978 to 1988, most helps to account for the finding?

(A) Glass bottles are significantly heavier than aluminum cans of comparable size.

(B) Recycled aluminum cans were almost all beverage containers, but a significant fraction of the recycled glass bottles had contained products other than beverages.

(C) Manufacturers replaced many glass bottles, but few aluminum cans, with plastic containers.

(D) The total weight of glass bottles purchased by households increased at a slightly faster rate than the total weight of aluminum cans.

(E) In many areas, glass bottles had to be sorted by color of the glass before being recycled, whereas aluminum cans required no sorting.

答案选C，可以理解，但为什么A错了呢？

prayer

however往后的句子，尽管铝制品回收比玻璃回收更广泛，但是发现居民的垃圾堆里玻璃重量占比下降的更多。实际上应该是铝制品的下降多才对，结果竟然是相反的，那么就是其他原因造成的，不仅仅是recycle。所以C中说玻璃瓶被塑料瓶给替代了，能解释玻璃瓶减少的多。
A说玻璃瓶比铝制品更重无法推出玻璃瓶在垃圾重量占比下降更多。比如重量=数量×单个重量，铝制品数量多，玻璃瓶单个重量大，那个总重量是没法比较的。