Final answer:
Legally, refrigerants can only be purchased by individuals who are certified under the EPA's Section 608 or Section 609 certification programs, regardless of age or possession of a driver's license. Completion of an environmental awareness course is not enough to purchase refrigerants without the proper certification.
Step-by-step explanation:
A non-certified person may not legally purchase refrigerant in the United States. Under the Clean Air Act, administered by the Environmental Protection Agency (EPA), refrigerants cannot be sold to individuals who are not certified under the EPA's Section 608 or Section 609 certification programs.
Specifically, Option A stating that they are over 18 years old, Option D stating that they have a valid driver's license, and Option C stating they provide proof of certification within 30 days do not meet the requirements for purchasing refrigerants. The correct process requires obtaining the appropriate EPA certification beforehand. While Option B regarding the completion of an environmental awareness course may be beneficial, it alone does not grant the legal authority to purchase refrigerants without the proper certification.