Which of the following is a reliable way for consumers to assess the quality of a supplement?

Look for the USP seal of approval and the NSF international seal of approval on the product label.

Explanation:

Although the options for this question are not included, one of the ways in which consumers can assess the quality of a suplement is by looking for the USP seal of approval and the NSF international seal of approval in the label of the product. These two markers are designed to reassure the consumer of the legality and the quality of a supplement.

b) to encourage free trade