Final answer:
When purchasing a product with pseudoephedrine/ephedrine/phenylpropanolamine, the customer is required to present a valid ID, such as a driver's license or passport.
Step-by-step explanation:
When purchasing a product with pseudoephedrine/ephedrine/phenylpropanolamine, the customer is required to present a valid ID, such as a driver's license or passport. This is because these substances can be used to illegally manufacture drugs like methamphetamine. The sale of such products is regulated by the DEA (Drug Enforcement Administration) and FDA (Food and Drug Administration) to prevent their misuse and ensure public safety.