C. Both employees and managers is the most logical answer.
Explanation:
Managers must set and enforce safety protocols, but in the end it's up to the employees to follow the safety protocols. If they fail to follow safety protocols, then any resulting accident is on themselves. If they do, however, follow safety protocols, and the accident is outside what they personally can handle, then it is then on the manager.
This means that when the person stops taking the drug they have physical and psychological symptoms of withdrawal. This can be muscle cramping, diarrhea, and anxiety. (Google.)
