If a person chooses to walk rather than drive, there is one less vehicle emitting pollution into the air than there w...

Irina on July 21, 2019

@Dberbari,

This is a strengthen question, which means we are looking for an answer choice that would most support the author's conclusion.

Let's briefly look at the structure of the argument:

Pr: A person chooses to walk, there is one less vehicle emitting pollution.
C: If people would walk whenever it is feasible, pollution would be greatly reduced.

(A) clearly weakens the argument as it directly attacks the premise. If a car passenger chooses to walk, the car still remains on the road, and no reduction in pollution occurs;
(B) is the correct answer choice because it demonstrates the correlation between the number of people driving and congestion, and congestion and pollution. If one chooses to walk instead of drive, there are less chances of congestion, i.e. less non-moving vehicles on the road, and less pollution overall. Even though non-moving vehicles emit less pollution than moving vehicles, having more cars on the road contributes to more congestion -> more non-moving vehicles on the road -> more pollution;
(C) is irrelevant, the author merely argues that the pollution would be greatly reduced, rather than discussing the impact of various types of vehicles on pollution levels;
(D) is again irrelevant, if anything it would weaken our premise. If a bus passenger chooses to walk, the bus still remains on the road;
(E) weakens the argument. If one's passengers have to drive themselves when their driver chooses to walk, there is no net reduction of vehicles on the road.

Let me know if this makes sense.

Dberbari22 on July 21, 2019

Yes, that makes sense. Thank you!

Ravi on July 22, 2019

@Dberbari22, great! Let us know if you have any other questions!