What type of identification is required for a patient to purchase a CV?

To purchase a controlled substance classified as a Schedule V (CV) in Arkansas, the law requires that individuals present a valid form of identification that proves their identity and age. A driver's license is a widely accepted form of ID because it provides verification of both identity and age, fulfilling the legal requirements necessary to make such a purchase.

While a passport might also serve as a valid form of identification, it’s not as commonly used in everyday transactions like purchasing medications, particularly in a pharmacy setting. A student ID and an employee badge typically do not carry the necessary legal verification required by pharmacies to sell controlled substances; they often lack the age verification or government endorsement that is inherent to a driver's license. Therefore, the driver's license is explicitly recognized in regulatory contexts as a suitable and proper identification for this purpose, making it the correct answer in this scenario.