求救OG12-79,谢谢！

真不甘心帖子就这样沉下去，再发一遍。恳请各位牛牛帮忙呀！

79. In countries where automobile insurance
includes compensation for whiplash injuries
sustained in automobile accidents, reports of
having suffered such injuries are twice as
frequent as they are in countries where whiplash
is not covered. Presently, no objective test for
whiplash exists, so it is true that spurious reports of
whiplash injuries cannot be readily identifi ed.
Nevertheless, these facts do not warrant the
conclusion drawn by some commentators that in the
countries with the higher rates of reported whiplash
injuries, half of the reported cases are spurious.
Clearly, in countries where automobile insurance
does not include compensation for whiplash,
people often have little incentive to report
whiplash injuries that they actually have suffered.
In the argument given, the two boldfaced portions play
which of the following roles?
(A) The fi rst is a claim that the argument disputes;
the second is a conclusion that has been based
on that claim.
(B) The fi rst is a claim that has been used to
support a conclusion that the argument accepts;
the second is that conclusion.
(C) The fi rst is evidence that has been used to
support a conclusion for which the argument
provides further evidence; the second is the
main conclusion of the argument.
(D) The fi rst is a fi nding whose implications are at
issue in the argument; the second is a claim
presented in order to argue against deriving
certain implications from that fi nding.
(E) The fi rst is a fi nding whose accuracy is evaluated
in the argument; the second is evidence
presented to establish that the fi nding is
accurate.

这道题没有很明显的标志词，为了不陷入内容里，它的做题思路应该是怎样的呢？还有OG12-77也是同样的没有标志词，这类句子作用题应该怎样做呢？谢谢！