If the Standard Deviation of a Data Set Is 0

Multiple Choice

If the standard deviation of a data set is 0,

A) the data set is symmetric, and the negative values cancelled out the positive values.
B) the mean of the data set must also be 0.
C) a calculation error must have been made, as the standard deviation cannot be 0 when the data set has positive values.
D) all of the observations in the data set must be the same.
E) none of the above.