Critical Reasoning

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.

[spoiler]OA: c [/spoiler]

Good question - I though it was A at first looking just for the weight clause.

But overall C has better fit, due to the fact the glass was replaced in comparison to aluminium cans in the same period and hence net reduction in weight.

The decline might be due to 2 factors instead of one that is mentioned: cycling.Replacement is another one.When x(cycling)+y(Replacement) causes decline.And in the question stem,it is mentioned that cycling does not cause decline of glass(as more Aluminium cycling is prevalent than glass),we have to look for another factor here i.e y(replacement).