Emily,Zeke,Harry,& Brook each conducted surveys on the number of books people have

Question

in their homes. Then they answered the question below.
"MUST ALL MEASURES OF CENTRAL TENDENCY
APPEAR AS A NUMBER IN A SET OF DATA COLLECTED?
A. Emily says this is always true because all the measures of central tendency also have to be in the numbers in the set of data.
B.Zeke says this is never true because all the measures of central tendency are never numbers in the set of data.
C.Harry says this is sometimes true because the mean and median may or may not be in the set of data, but the mode is always in the set of data.
D. Brook says this is sometimes true because the mean and mode may or may not
be in the set of data, but the median is always in the set of data.
WHY?