Which of the Following Statements About the Mean IS True

Which of the following statements about the mean IS true?

A) If you have open-ended classes in a grouped frequency distribution is is necessary to determine a nominal limit to the class
B) When reporting the value of the mean, is it usual to present the value with the same number of decimal places as the original data
C) The sum of deviations from the mean is always the same as the number of data points (frequency)
D) The mean is the least used of all the ways of presenting measures of location