To measure an investment risk, you may use all of the following except:

A. Time value of money
B. range of returns
c. standard deviation of returns
d. subjective measures of risk

To determine which option is the correct answer, let's break down the question and examine each choice.

A. Time value of money: The time value of money refers to the concept that money available in the present is worth more than the same amount in the future due to its potential earning capacity. While this concept is vital in evaluating the potential returns of an investment, it is not specifically used to measure investment risk.

B. Range of returns: The range of returns provides a measure of the spread between the minimum and maximum returns that an investment may generate. This metric helps capture the variability or fluctuation in investment performance and is commonly used to assess investment risk.

C. Standard deviation of returns: The standard deviation of returns is a statistical measure that quantifies the dispersion of a series of returns around the average or expected return. It provides an estimation of the investment's volatility and is widely used as a measure of investment risk.

D. Subjective measures of risk: Subjective measures of risk are softer and less quantifiable metrics used to assess risk perception. They may involve personal opinions, judgments, or qualitative assessments. While subjective measures are relevant in gauging an individual investor's comfort level or perception of risk, they are not typically used as objective measures to evaluate investment risk.

Based on the above analysis, the correct answer is option D. Subjective measures of risk. This option does not align with the objective and quantitative methods commonly employed to gauge investment risk.