【正确答案】 A

【答案解析】 Argument Evaluation
   Situation  Last year in Wareland, a much higher percentage of drivers 24 and under than of drivers 65 and
              older were in serious accidents.
   Reasoning  What must be true for the observation about the accident rates to support the conclusion that the greater
              experience and caution of drivers 65 and older make them safer behind the wheal than the younger
              drivers? Several factors other than greater experience and caution could explain the lower accident
              rate among the older drivers. For example, the older drivers might simply drive much less than the
              younger ones, but still get in just as many accidents per mile driven. Or perhaps because the older
              drivers are more often retired, their schedules less often lead them to drive at times of day when
              accident rates are greater for everyone. Or they might be more likely to live in rural areas with less
              traffic and lower accident rates. The argument depends on assuming that none of these factors fully
              explains the difference in accident rates.
   A   Correct. Although we are given no information about the possible extent of any difference in average miles driven, the (somewhat vague) information that drivers 65 and older drive very many fewer miles per year, on average, than drivers 24 and younger would cast serious doubt on the statistical argument given. The argument assumes that the difference in miles driven is not sufficiently substantial to undermine the argument.
   B   The argument is only about the discrepancy between the percentages of the drivers in two specific age groups who were in serious accidents last year. The percentages of licensed drivers who fall in these age groups are irrelevant.
   C   Even if drivers 65 and older are just as likely as younger drivers to drive in inclement weather, they may do so far more carefully than the younger drivers, so the older drivers' greater experience and caution could still explain their lower accident rates.
   D   Even if greater experience does not explain the difference between the accident rates of the two younger groups of drivers, it might still explain the differences between the accident rate of those two younger groups taken together and that of drivers aged 65 and older.
   E   The accident rate could be lower for drivers in late middle age than for those 65 and older because drivers in late middle age are also cautious and experienced, but their reflexes and vision tend to be less impaired. Even if that were true, the experience and caution of the drivers 65 and older might still make them safer than drivers 24 and under.
   The correct answer is A.