Final answer:
The label that signifies that a vitamin/mineral supplement was produced under pure and reliable standards is USP (United States Pharmacopeia).
Step-by-step explanation:
When taking a vitamin/mineral supplement, the label that signifies that the supplement was produced under pure and reliable standards is USP (United States Pharmacopeia). The USP is a non-profit organization that sets quality standards for drugs and dietary supplements in the United States. Their standards ensure that the supplement is safe, pure, and accurately labeled.