B is the right answer: It would definitely be a Bad Idea to announce to all students that Frank can’t be trusted because he has a drinking problem. This would be unkind and doesn’t serve anybody!
A, C and D are GOOD Ideas and helpful actions that would serve Frank and the Students: Regular participation in the AA program is a well-established pathway to long-term sobriety. Ongoing participation in AA could be a requirement for Frank in order to return to and continue teaching. Until the yoga studio has confidence that Frank is maintaining sobriety, Frank should not be allowed to teach. This is to make sure classes are taught correctly, respectfully, and within a safe environment for students. Lastly, Keeping EPS informed is important. They can provide additional support and recommendations if needed. When Frank returns to teaching, if he should relapse, EPS would already have background to provide further guidance and recommendations.