Concept:A scale of preference is a list that ranks an individual’s wants according to importance.Explanation:The scale of preference arranges wants in descending order of priority, starting with the most important want.It helps a consumer make rational choices when resources are limited, so the most pressing needs are satisfied first.Therefore, it directly shows consumer’s wants in order of priority, not income levels, utilities, or opportunity costs alone.Answer:D. consumer's wants in order of priority.