关于OG蓝皮书里面逻辑部分的一道题目的不理解

sherrygong1101

Pro-Tec Insurance Company has recently been paying out more on car-theft claims than it expected. Cars with special antitheft devices or alarm systems are much less likely to be stolen than are other cars. Consequently Pro-Tec, as part of an effort to reduce its annual payouts, will offer a discount to holders of car-theft policies if their cars have antitheft devices or alarm systems.

Which of the following, if true, provides the strongest indication that the plan is likely to achieve its goal?

A. The decrease in the risk of car theft conferred by having a car alarm is greatest when only a few cars have such alarms.
B. The number of policyholders who have filed a claim in the past year is higher for Pro-Tec than for other insurance companies.
C. In one or two years,the discount that Pro-Tec is offering will amount to more than the cost of buying certain highly effective antitheft devices.
D. Currently, Pro-Tec cannot legally raise the premiums it charges for a given amount of insurance against car theft.
E. The amount Pro-Tec has been paying out on car-theft claims has been greater for some models of car than for others.

这道题目我当时的确选择了答案C，但是在复习的时候我觉得答案A也可以作为正确选项，分析思路如下：

Answer A can also be taken in the following way: the decrease of the risk of car theft if they are equipped with a car alarm is greatest when only a few cars have such alarms. So, if it is true, it means this kind of decrease is greatest so that it can help the plan to achieve its goal. Am I right?

求NN解答阿，跪谢！

sherrygong1101

thanks a lot! i got it

HermanLu

前提是when only a few cars have such alarms 满足吗？   

最重要的是 discount 有什么关系？

roylist

你想反了。A只能weaken。人少了alarm才有效。那人多了不是没效果了！