To reduce carbon emissions, the city council proposes replacing all public buses with electric models. They argue this change will significantly lower the city's overall carbon footprint. Which of the following, if true, most weakens the city council's argument?
✓ Correct Answer: Option A
The argument assumes electric buses reduce the carbon footprint. If the electricity source itself is high-emission, the overall carbon footprint might not decrease, or even increase, directly weakening the proposal's intended effect.