Answer: The risk per unit of mean return.

**Explanation:** The coefficient of variation (CV) is a standardized measure of dispersion that expresses the risk (standard deviation) per unit of mean return. This makes it useful for comparing the risk-adjusted performance of different investments, especially when their means differ significantly. - **Option A** is correct because the CV directly measures the amount of risk (standard deviation) relative to the mean return. - **Option B** describes the Sharpe ratio, which measures the mean excess return (return above the risk-free rate) per unit of risk, not the CV. - **Option C** refers to the mean absolute deviation (MAD), which calculates the average of absolute deviations from the mean, not the CV.

Author: LeetQuiz Editorial Team