Final answer:
Calories, ingredients, and a percentage of certain micronutrients are required on a nutrition facts label, but the manufacturer's contact information is not.
Step-by-step explanation:
According to the regulations that govern nutrition facts labels in the United States, calories (b), ingredients (c), and a percentage of certain micronutrients must be included on a supplement label. However, the manufacturer's contact information (d) is not required to be listed on a nutrition facts label. The primary function of these labels is to inform consumers about the nutrient content in one serving of the food, and how it contributes to their daily diet.