IMO C. Reasons:
The passage suggests that to reduce accidents, all the necessary radical steps should be taken w.r.t. driver's alertness on the road. Hence, the assumption that the expert draws is that accidents are caused because of negligence on driver's part.
Traffic Safety Expert: In order to achieve a substantial reduction in the extremely high number of car accidents in our country, we should implement a radical new safe driving plan. Seat belts and air bags would be eliminated from the driver's side of all automobiles to provide the driver with the strongest possible incentive to drive safely. Further,an electroshock system would administer shocks to the driver if he or she exceeds the speed limit or engages in other unsafe driving practices.
In declaring that the radical new safe driving plan will help to reduce accident rates, the author assumes which of the following?
(A) Many car accidents are caused, at least partially, by naturally occurring conditions such as rain and fog.
Irrelevant(B) Accidents in which one or both participants exceed 60 miles per hour account for a majority of all fatal car accidents.
We are not talking about fatal or non fatal accidents. Hence, irrelevant(C)A significant number of accidents are the result of negligence or other unsafe driving practices on the part of the driver.
Like stated before, this is correct(D) To alleviate safety concerns, citizens should be allowed to reinstall their drivers' side seat belts and air bags at their own expense. this can be the addition to the safety expert's statement but definately not the assumption. Hence, incorrect
(E) If not implemented properly, electroshock systems can cause heart attacks and other health problems.
irrelevantSource: MGMAT 4th Edition