问题如下：
An investor often use a company's cost of equity as a proxy for:
选项：
A. the average required return.
B. the minimum required return.
C. the maximum required return.
解释：
B is correct.
Companies wish to fund at the lowest possible cost. So the cost of equity may be used as a proxy for the minimum required rate of return.
麻烦解释一下？ 谢谢。