C
Charles: During recessions unemployment typically rises. Thus, during a recession air pollution due to automobile exhaust decreases, since fewer people commute in cars to jobs and so cars emitting pollutants into the air are used less. Darla: Why think that air pollution would decrease? During a recession fewer people can afford to buy new cars, and cars tend to emit more pollutants as they get older. Which one of the following most accurately describes how Darla's response is related to Charles's argument?
A: It calls into question the truth of the premises that Charles uses to support his conclusion.
B: It presents an argument showing that the premises in Charles' s argument support an absurd conclusion that Charles has overlooked.
C: It presents an additional consideration that weakens the support given to Charles's conclusion by his evidence.
D: It argues that Charles's conclusion is true, although not for the reasons Charles gives to support that conclusion.