The correct answer is the following: option D. The code of conduct that Joey violated was the one of competence. To be competent at work is one of te codes of conduct that all psychiatrists need to aim to in the professional careers. Competence is a cluster of related abilities, commitments, knowledge and skills that enable a person to act effectively in their job.
When Joey accidentally gave a client a prescription for the wrong medication, he was not competent, as he made a mistake that made him not act effectively in his job.