In calculating the variance of a portfolio's returns, squaring the deviations from the mean results in:
I. Preventing the sum of the deviations from always equaling zero
II. Exaggerating the effects of large positive and negative deviations
III. A number for which the unit is percentage of returns
A. I only
B. I and II only
C. I and III only
D. I, II, and III
Answer: B. I and II only