Passage Summary: Charles argues that because fewer people have jobs to drive to during a recession, the total amount of car pollution will drop.

Conclusion: Air pollution from automobile exhaust decreases during a recession.

Reasoning: Recessions lead to higher unemployment, which means fewer people are driving to work, resulting in less car usage.

Analysis: Charles's argument has a significant gap: he assumes that a decrease in one type of driving (commuting) will result in an overall decrease in pollution. He fails to account for the possibility that the remaining driving could be more polluting or that other types of driving might increase. For his conclusion to be necessary, he must assume that the pollution increase from older cars (as Darla suggests) does not completely cancel out the pollution savings from fewer commuters. Look for an answer that ensures the 'savings' from less commuting aren't totally negated by other factors.