题目选项分析

Which of the following best completes the passage below?

The more worried investors are about losing their money, the more they will demand a high potential return on their investment：great risks must be offset by the chance of great rewards.This principle is the fundamental one in determining interest rates, and it is illustrated by the fact that ________ .

【选项】at any one time, a commercial bank will have a single rate of interest that it will expect all of its individual borrowers to pay