Premise:
1) NBA -> sole responsibility of each driver to use or not use seat-belts (This means safety of the driver is the driver's own responsibility)
2) NBA -> want to change legislature to enable drivers drive without having to use a seat-belt (underlying principle: responsibility falls on the driver himself)
3) 1st step to implementing NBA's proposal -> allow SOME drivers to go without seat belt
4) Research -> most mothers usually drive within 20 miles from home
5) Seat belts makes mothers nervous: Mothers running late
Conclusion:
6) Mothers driving within 20 miles from home should be allowed to go without seat belts
The passage here argues that mother should be allowed to drive without seat belts because the seat belts makes them nervous. Besides, they drive no further than 20 miles from home.
This assumes that any driving within 20 miles is relatively safe. The only reason that the journey can become a hazard is because mothers are unnerved by the seat belts.
In this, I feel A is a good choice.
We are already told in the passage that most mothers keep their driving within 20 miles from home. We do not need the extra statistics presented in choice E (97% of driving < 20 miles).
A also stress that mothers are a nervous lot, making them wear seat belts are going to make them more nervous. The rest of the bits in A are inconsequential. I think they're there for cosmetic reasons.
E says that 97% of mothers drive within 20 miles. And within 20 miles, driving is safe. But I feel this is not sufficient because the passage already says most mother drive within a 20 miles range but they can still get into trouble because the mere use of seat belts makes them anxious.
I'll take A.