单选题 Technically a given category of insurance policy is underpriced if, over time, claims against it plus expenses associated with it exceed total income from premiums. But premium income can be invested and will then yield returns of its own. Therefore, an underpriced policy does not represent a net loss in every case.
The argument above is based on which of the following assumptions?

A、 No insurance policies are deliberately underpriced in order to attract customers to the insurance company offering such policies.
B、 A policy that represents a net loss to the insurance company is not an underpriced people in every case.
C、 There are policies for which the level of claims per year can be predicted with great accuracy before premiums are set.
D、 The income earned by investing premium income is the most important determinant of an insurance company's profits.
E、 (E) The claims against at least some underpriced policies do not require paying out all of the premium income from those policies as soon as it is earned.

【正确答案】 E

【答案解析】[解析] 假设是结论成立的必要条件，本题推理的结论是“an underpriced policy does not represent a net loss in every case.”而(E)选项明显可以作为上述结论的假设，且“at least some underpriced policies”与“not... in every case”相对应，说明由于至少有一些索赔不需支付完所有收入，所以可以有一部分保险收入用以投资以取得收入，所以说明原因可行有意义，因此(E)正确；(B)与段落推理相违背；(D)有两个错误：①段落中若无绝对化语言，选项中也应无绝对化语言，(D)中的“the most”得不到。②(D)只说明了决定保险利润的因素，但究竟能否有保费收入进行投资我们并不知道，因此(D)不正确。