求问一道XDF网络课堂的逻辑题

坤kun

Scientists now believe that artificial-hip implants, previously thought to be safe, may actually
increase the risk of cancer in recipients after about 45 years of use. Though these implants do
improve the quality of recipient’s lives, the increased risk of cancer is an unacceptable price to pay
for these improvements. Therefore, they should be banned.
 Which of the following, if true, is the strongest counterargument to the argument above?
(A) Artificial-hip implant surgery can severe complications, such as infection, chronic fever, and
bone degeneration, and these complications can themselves be crippling or even fatal.
(B) Almost all artificial-hip implant recipients receive their implants at an age when they are unlikely
to live more than an additional 30 years.
(C) Although artificial-hip implants increase the risk of cancer after about 45 year of use, a few of
the cancers they induce are not fatal.
(D) Since artificial-hip implants are not very common, banning them would cause little hardship.
(E) Although the benefits of artificial-hip implant surgery have remained substantially the same over
the past decade, the price of the surgery has risen considerably.

主要纠结在B\C选项上，我不知道为什么B对，为什么C不对，刚开始看GMAT，可能大家觉得比较问题比较弱智~拜谢NN们啦！

sdcar2010

This is just common sense.

B explains why the risk of cancer after 45 years of use is not a sufficient reason to ban the implant. By that time, most of the patients have already died. This is a weakener, thus, the correct answer.

C says that A FEW of the cancers the implants induce are not fatal. This means that MOST of the cancers the implants induce are FATAL. This is a strengthener.