Which of the following best describes nominal data?

• A. Data that permit subtraction but not ordering, used primarily for calendar-based variables.
• B. Numeric measurements with an absolute zero allowing multiplication and division to be meaningful.
• C. Ordered categories where differences are equal and ratios of values are interpretable as proportions of a whole.
• D. Data consisting of categories or labels with no inherent order; only counting/frequencies are meaningful.

Answer: (D)