Official Solution:
From 2000 to 2010, beverage containers accounted for a steadily decreasing percentage of the total weight of domestic garbage in the Brazil. The increasingly widespread practice of recycling aluminum and plastic was responsible for most of this decline. However, although aluminum recycling was more widely practiced in this period than plastic recycling, it was found that the weight of plastic bottles in domestic garbage declined by a greater percentage than the weight of aluminum cans.
Which of the following, if true of the Brazil in the period 2000 to 2010, most helps to account for the finding?
A. Plastic 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 plastic bottles had contained products other than beverages.
C. Manufacturers replaced many plastic bottles, but few aluminum cans, with polymer containers.
D. The total weight of plastic bottles purchased by domestics increased at a slightly faster rate than the total weight of aluminum cans.
E. In many areas, plastic bottles had to be sorted by color of the plastic before being recycled, whereas aluminum cans required no sorting.
Background:
From 2000 to 2010 in Brazil, the weight of plastic bottles in domestic garbage declined by a greater percentage than that of aluminum cans, despite aluminum recycling being more prevalent than plastic recycling.
Objective:
To find the reason why the weight of plastic bottles in garbage declined more than aluminum cans, despite lower rates of plastic recycling.
Analysis of Answer Choices:
A. Plastic bottles are significantly heavier than aluminum cans of comparable size.
Relevance: This doesn't directly explain why the weight of plastic bottles declined more, especially considering less frequent recycling.
Conclusion: Not suitable, as it doesn't address the decrease in garbage contribution.
B. Recycled aluminum cans were almost all beverage containers, but a significant fraction of the recycled plastic bottles had contained products other than beverages.
Relevance: This implies that non-beverage plastic containers are also recycled, but doesn't account for a reduction in the plastic bottles' garbage contribution.
Conclusion: Insufficient, as it does not directly explain the decline in plastic bottles in domestic garbage.
C. Manufacturers replaced many plastic bottles, but few aluminum cans, with polymer containers.
Relevance: This suggests a significant reduction in the production and disposal of plastic bottles, which directly leads to a decrease in their presence in domestic garbage.
Conclusion: Suitable, directly addresses the disproportionate decline in plastic bottle waste.
D. The total weight of plastic bottles purchased by domestics increased at a slightly faster rate than the total weight of aluminum cans.
Relevance: If the total weight of plastic bottles increased, we would expect an increase, not a decrease, in their garbage contribution.
Conclusion: Contradicts the observed trend, thus inappropriate.
E. In many areas, plastic bottles had to be sorted by color of the plastic before being recycled, whereas aluminum cans required no sorting.
Relevance: Sorting complexity might impact recycling rates but does not directly relate to the decrease in garbage contribution.
Conclusion: Irrelevant to the specific decrease observed.
Conclusion:
Option C is the best answer because it provides a logical explanation for why plastic bottles would see a greater reduction in domestic garbage presence compared to aluminum cans, aligning with the switch to polymer containers reducing the number of plastic bottles used and disposed of. This supports the scenario despite lower recycling rates for plastic.
Answer: C