In Terms of Estimating the Population Variance,what Is One Disadvantage

Multiple Choice

In terms of estimating the population variance,what is one disadvantage of dividing SS by df to calculate sample variance?

A) It is an unbiased estimator.
B) It does not have minimum variance.
C) It underestimates the population variance on average.
D) None; there are no disadvantages of dividing SS by df to calculate sample variance.