题目：
For an investment portfolio, the Sharpe ratio is best described as a(n): （）
A. Relative measure that indicates risk per unit of mean return.
B. Absolute measure that indicates risk per unit of mean return.
C. Relative measure that indicates mean excess return per unit of risk.
答案：
参考答案：C
解析：
The Sharpe ratio is a relative measure that equals excess return of a portfolio (mean return less the risk free rate) divided by the standard deviation of the portfolio.
