Final answer:
The true statement is that the mode is always one of the numbers in the data. Other statements regarding mean and mode can be false, as the mean does not have to be a value from the data, and the relative size of mean and mode can vary with the data distribution.
Step-by-step explanation:
The correct statement is (a): Mode is always one of the numbers in the data. The mode is defined as the most frequently occurring value(s) in a dataset. Therefore, by definition, the mode must be a number that is included in the data set. Statements (b), (c), and (d) can be false in various circumstances. For example, the mean does not have to be a number that appears in the data set; it is the average of all the numbers. Mean < Mode and Median < Mode are not universally true because their relationship can vary depending on the distribution of the data.