GRE阅读36套一道题目求解答

GRE阅读36套一道题目求解答
Authorities in California required drivers to use their
headlights on a certain road during the daytime as well
as at night and found that annual accident rates on the
road fell 15 percent from the previous level.They
concluded that applying the dayti me rule statewide
would lead to a similar reduction in accidents.
1.Which of the following,if true,most strengthens the
authorities' argument?
(A) Because an alternate route became available,the
volume of traffic on the test road decreased during
the test period.
(B) Drivers were informed of the requirement to use
their headlights on the test road by means of a
series of three conspicuous signs in each direction
of travel.
(C) Under certain conditions,among them fog and
heavy rain,most drivers in California already use
their headlights during the daytime.
(D) Full-scale application of the daytime rule would
cause headlight bulbs to burn out sooner than
they currently do and thus to require more
frequent replacement.
(E) The test road was selected to include a great
variety of the sorts of road conditions that drivers
in California are likely to encounter.
但我不是很理解这五个选项,和文章中作者声明的论点有什么关系吗?