A city’s public transportation board has decided to cut costs by reducing the frequency of its bus service from an average of eight minutes to an average of ten minutes between buses. The board announced that it can do so without seriously reducing the quality of service.
Which of the following statements, if true, would most strengthen the validity of the board’s announcement?
(A) The less frequent use of the buses will lower maintenance
costs, resulting in savings that can be used for much-needed
repairs of the city’s pedestrian bridges.
(B) At rush hour, congestion in the city slows bus service by thirty
percent.
(C) Because of a robust economy in the city, passenger patronage
has increased substantially in recent years.
(D) The public transportation board has recently gathered data on
the levels of ridership on all bus lines, showing that some lines
are used by many more riders than others.
(E) The contract with the bus drivers union stipulates that the city
not lay off any drivers because of reduced bus service.

OA A. But shouldn't the answer cater to the service quality rather than the cost.

btw source is https://www.beatthegmat.com/critical-rea ... t-t60.html