Question

which of the following was not discussed as a problem with normal reference ranges?

race

diet

contamination

attitudes

Explanation:

To determine which was not discussed as a problem with normal reference ranges, we analyze each option. Race, diet, and contamination can impact physiological measures (thus relevant to reference ranges). Attitudes are psychological and not typically a factor in normal reference range problems (which relate to biological/health - related factors like race - based differences, diet - induced changes, or contamination - related errors in measurements).

Answer:

D. Attitudes