Ten years ago, the country of vorland adopted new automobile safety regulations requiring airbags and better seat belts in all new automobiles. since then, the annual number of drivers and passengers hospitalized overnight or longer for injuries sustained in automobile accidents has steadily declined. clearly, the regulations have made vorland's automobiles safer for drivers and passengers who are involved in accidents. which of the following is an assumption on which the argument depends? (a) the citizens of vorland generally obey all national and local speed limits. (b) of the patients treated at hospitals in vorland, the percentage treated being treated for injuries sustained in automobile accidents has decreased in the past ten years. (c) the safety improvements required by the regulations have not significantly affect the price of new automobiles. (d) there has been no increase in speed limits on vorland's major highways over the past ten years. (e) over the past ten years, there has not been a steady decline in the annual number of drivers and passengers involved in automobile accidents in vorland.