The dot plots represent the distributions of values in data sets X and Y.

Data Set X has dots at 10, 11, 12, 12, 12, 13, 14.
Data Set Y has dots at 10, 10, 11, 12, 13, 14, 14.

Which of the following statements must be true?

I. The median of data set X is equal to the median of data set Y.

II. The range of data set X is equal to the range of data set Y.

III. The standard deviation of data set X is equal to the standard deviation of data set Y.