A.) All the observations are the same value
Step-by-step explanation:
One of the statistical measures used to determine the spread or variability of a dataset is the variance or standard deviation. The standard deviation determines how a set of value varies about the mean value.
Mathematically,
Variability or spread = mean + number of standard deviations
Hence, a standard deviation of 0 ; means they there is no variability in the dataset. Hence, a standard deviation of 0 means all observations are of the same value.