OG 10th CR 第四题的解释，看不懂。求助阿

4.

Insurance Company X is considering issuing a new policy to cover services required by elderly people who suffer from diseases that afflict the elderly. Premiums for the policy must be low enough to attract customers. Therefore, Company X is concerned that the income from the policies would not be sufficient to pay for the claims that would be made.

Which of the following strategies would be most likely to minimize Company X’s losses on the policies?
A. Attracting middle-aged customers unlikely to submit claims for benefits for many years.
B. Insuring only those individuals who did not suffer any serious diseases as children
C. Including a greater number of services in the policy than are included in other policies of lower cost
D. Insuring only those individuals who were rejected by other companies for similar policies

E. Insuring only those individuals who are wealthy enough to pay for the medical services

答案如下：

Insurance companies can improve the ratio of revenues to claims paid, thus minimizing losses, if they insure as many people belonging to low-risk groups as they can. Because the strategy described in A adds a low-risk group to the pool of policyholders, this choice is the best answer. B is irrelevant, since no link is established between childhood diseases and diseases affecting the elderly. C is inappropriate, since increasing the number of services covered is unlikely to minimize losses. D is inappropriate, since it would increase the likelihood that claims against the policy will be made. Because policyholders will file claims against the policy for services covered rather than pay for the cost of the services themselves, E is irrelevant.

这里的' file claims against the policy for services covered '指的是什么呢？

File sth against 是不是个固定搭配？什么意思啊？

跪求解。。。