It’s not clear whether the average person buying a car knows anything about how minivans perform in crash tests. In any case, minivans don’t perform particularly well compared to other cars, so (A) doesn’t help establish the author’s theory.

If anything, this might weaken the argument, because we would expect that cars driven primarily by low-risk drivers should have fewer accidents per vehicle than other cars. (B) indicates this expectation isn’t met.

This helps establish that minivans are the safest vehicles. More passengers per vehicle combined with fewest injuries per vehicle is strong evidence of safety. But it doesn’t reveal anything about the cause of this safety; is it the vehicle itself or the kind of driver?

This suggests part of the reason minivans are safer than other vehicles is their size. If anything, this might weaken by suggesting there are inherent aspects of the minivan that contribute to its safety.

This shows the minivan has features that make it inherently less safe than other vehicles. Thus, we have even less reason to believe the minivan’s safety is due to being inherently safer than other cars. This eliminates an alternate explanation for the minivan’s safety.