Risk per unit of return or stand alone risk is represented by

The correct answer is C. coefficient of variation.

The coefficient of variation is a measure of the relative variability of a set of data. It is calculated by dividing the standard deviation by the mean. A higher coefficient of variation indicates that the data is more spread out, while a lower coefficient of variation indicates that the data is more tightly clustered around the mean.

The coefficient of variation is often used to compare the risk of different investments. For example, if two investments have the same expected return, but one has a higher coefficient of variation, then the second investment is considered to be riskier.

The other options are incorrect.

• Option A, coefficient of standard, is not a valid measure of risk.
• Option B, coefficient of return, is a measure of the expected return of an investment.
• Option D, coefficient of deviation, is not a valid measure of risk.