Which of the following would most weaken the argument that urban green roofs offer stormwater management and other benefits?

• A. Green roofs provide insulation but no stormwater management.
• B. Green roofs gained public support.
• C. There is strong evidence of energy savings.
• D. Installation costs have fallen.

Answer: (A)

The main idea being tested is how to weaken an argument by challenging a key claimed benefit. The argument says urban green roofs offer stormwater management along with other benefits. The strongest way to weaken that claim is to present a statement that directly denies the specific benefit in question. Saying that green roofs provide insulation but do not offer stormwater management challenges the core assertion about that particular benefit, so it undermines the overall argument that green roofs deliver stormwater management and other related advantages.

The other options would either support the argument or be neutral toward it. Gaining public support, evidence of energy savings, or lower installation costs would help the case for adopting green roofs, not weaken it.