Critical Reasoning

Since the mayor's publicity campaign for Greenville's bus service began six months ago, morning automobile traffic into the midtown area of the city has decreased seven percent. During the same period, there has been an equivalent rise in the number of persons riding buses into the midtown area. Obviously, the mayor's publicity campaign has convinced many people to leave their cars at home and ride the bus to work.

Which of the following, if true, casts the most serious doubt on the conclusion drawn above?

(A) Fares for all bus routes in Greenville have risen an average of five percent during the past six months.

(B) The mayor of Greenville rides the bus to City Hall in the city's midtown area.

(C) Road reconstruction has greatly reduced the number of lanes available to commuters in major streets leading to the midtown area during the past six months.

(D) The number of buses entering the midtown area of Greenville during the morning hours is exactly the same now as it was one year ago.

(E) Surveys show that longtime bus riders are no more satisfied with the Greenville bus service than they were before the mayor's publicity campaign began.

Hello friends, please provide answer and a little explanation to dispel my confusions. Thanks.

OA to be followed.

C is the correct answer.

Mayor has been campaining since last 6 months for Greenville public transport.
At the same time traffic congestion has reduced and number of people using bus service have increased.
Author concludes that these change in improvement of public transport was due to mayor's campaign effort.

To weaken the argument we need show that people started using public transport due to different reason but not mayor's campaign.

C weakens the argument .Since road constructions in the midtown area reduced number of lanes for vehicle commuters, people were forced to use public transport.

But why not A. May be increase in road fares caused ppl to switch to public transport. How to eliminate A.

The author says people have stopped using their vehicles and have switched to bus.

C clearly says the reason why people have stopped using vehicles. But A merely talks about bus fare...How does increase in bus fare relate to reduction of vehicles..Infact, people might prefer their own transport than to pay heavy fare. Hence A cannot be the answer.

gmat620 wrote:But why not A. May be increase in road fares caused ppl to switch to public transport. How to eliminate A.

In fact, A stengthens the argument. Despite increases in road fares, commuters switched to bus service.

I think, you assumed public transport = free.

I like the explanation on A.