CR assumption querry

Let’s first identify the conclusion. Here it says that the “greater experience and developed habits of caution possessed by drivers in the 65-and-older group make them far safer behind the wheel than the younger drivers are.” In other words, the experience and caution exercised by the older group make them safer than the younger group.

Now we need to find an assumption that does not challenge this conclusion.

(A) Drivers 65 and older do not, on average, drive very many fewer miles per year than drivers 24 and younger.

Here, this sounds like a good assumption. If the older drivers were to drive fewer miles on average, then it would break the argument. This, in fact, makes the comparison between old and young drivers made in the argument logical. It only makes sense to compare these two groups if the distance covered by the two groups is comparable.

(B) Drivers 65 and older do not constitute a significantly larger percentage of licensed drivers in Wareland than drivers ages 18-24 do.

This option isn’t entirely relevant as an assumption to the stated argument. The question of “licenced drivers” is not the issue here. Therefore you can eliminate this. Further, since it is given as a percentage without any relevant information to compare it with, you can disregard it.

(C) Drivers 65 and older are less likely than are drivers 24 and younger to drive during weather conditions that greatly increase the risk of accidents.

Clearly, this is out of scope. It does not impact our conclusion and can be eliminated.

(D) The difference between the accident rate of drivers under 21 and of those ages 21-24 is attributable to the greater driving experience of those in the older group.

Here the comparison is made between the two younger groups and does not lend usefully to the argument.

(E) There is no age bracket for which the accident rate is lower than it is for licensed drivers 65 and older.

This again does not talk about the experience or caution mentioned in the argument.

Hope this helps!