Which of the following is a reason for requiring a photo ID during the purchase of controlled substances?

Requiring a photo ID during the purchase of controlled substances is primarily aimed at ensuring the identity of the purchaser. This measure helps pharmacies and dispensaries confirm that the individual attempting to buy the medications is indeed who they claim to be. By checking the photo ID against the individual, pharmacists can prevent unauthorized persons from obtaining controlled substances, which is crucial in combatting prescription drug abuse and diversion.

While tracking customer purchases, verifying age, and preventing theft are also important factors in the broader context of controlled substance regulations, the most direct and critical reason for the requirement of a photo ID is to ensure that the person purchasing the medication is legitimately entitled to do so. This aligns with federal and state laws designed to regulate access to potentially harmful substances, maintaining public health and safety.