During a Cold Winter, the Temperature Stayed Below Zero for 10

Multiple Choice

During a cold winter, the temperature stayed below zero for 10 days (ranging from -20 to -5) . The variance of the temperatures of the 10 day period _____.

A) is negative since all the numbers are negative
B) must be at least zero
C) cannot be computed since all the numbers are negative
D) can be either negative or positive