Which of the following is NOT a method for disposal of controlled substances from a practitioner's inventory?

The correct response highlights that direct sale to the public is not an approved method for disposing of controlled substances from a practitioner's inventory. When it comes to controlled substances, there are strict regulations governing their disposal to prevent misuse or diversion. A practitioner cannot sell these substances to the public because it poses significant risks to public health and safety.

In contrast, methods such as utilizing an on-site method involve protocols to safely, securely, and legally destroy controlled substances in a manner that minimizes potential harm. Employing a reverse distributor is a common practice where licensed entities specialize in the handling and disposal of controlled substances, adhering to legal requirements. The return or recall of controlled substances also complies with regulatory frameworks that allow for safe and legal handling processes to manage expired or unwanted stock. Thus, direct sale to the public is not permissible, making it the correct answer as the method that does not fit within the legal framework for disposing of controlled substances.