The correct answer is D. Nominal . The CSSBB material defines nominal data as data consisting of names or categories only and explicitly states that no ordering scheme is possible . This is the exact wording needed to answer the question. Examples include labels such as colors, departments, shipping codes, or product categories where the values are simply different classes, not ranked positions.

By contrast, ordinal data do have an implied order, even though the differences between values may not be meaningful. Interval data have ordered values with meaningful differences but no true zero, and ratio data extend interval data by including an inherent zero so ratios are meaningful. The CSSBB table of measurement scales clearly distinguishes these four types. Therefore, when the question asks for the scale that classifies data into categories with no implied order, the correct and verified answer is D. Nominal .