Which of these is a measure of risk to reward earned by an investment over a specific period of time?

A. Coefficient of variation

B. Market deviation

C. Standard deviation

D. Total variation

The correct answer is A. Coefficient of variation.

Explanation:

Coefficient of variation is the risk of an asset or portfolio per unit of return.

Coefficient of variation = Standard deviation / Return

Lower the coefficient, better it is.

If portfolio have same return but different risk or same risk but different return then inventor will prefer portfolio with

higest return at a given level of risk or Lowest risk at given level of return

If portfolio have different returns with different risks, then protfolio with lower coefficient of variation is preferred.