What is a legal defense if someone under 21 is served alcohol in Arizona?

The correct choice emphasizes the importance of following established ID checking procedures as a legal defense when serving alcohol in Arizona. In any establishment that serves alcohol, it is crucial to verify the age of customers to comply with the law, which prohibits serving alcohol to anyone under the legal drinking age of 21. This procedure typically involves checking a valid form of identification, such as a driver's license or state ID, to ensure the individual is of legal age.

Implementing proper ID checking procedures demonstrates the establishment's commitment to responsible alcohol service and compliance with Arizona’s liquor laws. If an underage person is inadvertently served alcohol despite these protocols being followed correctly, the establishment may have a better legal standing in defending against any repercussions.

Other options, while they may seem relevant, do not provide a strong legal defense in this context. For example, refusing service does not address the situation after the fact, and getting a witness may not be practical or effective in proving compliance with the law. Serving only small amounts does not change the legal implications of serving alcohol to someone underage; the age of the individual is what is pivotal in this situation.