From 1978 to 1988, beverage containers accounted for a steadily decreasing % of the total weight of household garbage in the united states. the increasingly widespread recycling of aluminum and glass was responsible for most of this decline. however, although aluminum recycling was more widely practiced than glass recycling, it was found that the weight of glass bottles in household garbage declined by a greater % than the weight of the aluminum cans.
which of the following, if true of the united states in the period 1978 to 1988, most 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 the aluminum cans required no sorting.