Below is the Q. I understand how E is the answer. But I'm not so sure, why C cannot be the answer?
In Morigia the average age of cars that are still in use has historically been seven years, but now it is nearly nine years. Car manufacturers claim that the current poor economy has forced people to put off buying new cars, and thus when the economy improves, the average age of cars will return to former levels.
Which of the following, if true, most seriously calls into question the car manufacturers' prediction?
(A) Fewer cars per year are now being manufactured in Morigia than were being manufactured there five years ago.
(B) When the threat of job loss is particularly strong, people are reluctant to commit themselves to expensive purchases.
(C) The older a car is, the greater the amount of upkeep it requires.
(D) The air-pollution control devices now being used in cars manufactured in Morigia cost less than those that were used seven years ago.
(E) Most people in Morigia now believe that replacing an old car with a new one has very undesirable ecological consequences.