Problems caused by the leaching of pollutants from dumps and landfills are worst in countries with an annual per capita economic output of $4,000 to $5,000, and less severe for considerably poorer and considerably richer countries. This is so because pollution problems increase during the early stages of a country’s industrial development capita economic output is now $5,000, should begin to diminish in the next few years.
What this question is testing
Your task
Find the assumption the argument requires in order for its conclusion to hold.
Common trap
Answers that would help the argument but aren't strictly required (sufficient, not necessary).
Winning move
Negate each choice — the right one breaks the argument when negated.
Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.