A) For it does not require a life long commitment, and it is not C) because it can be any substance not just tobacco!
Thus your answer is A) gradually but completely withdrawing substances from use !
Have a happy life !
:D <span />
Relaxation can help lower your blood sugar levels.
True, a<span> symptom of schizophrenia could be having unusual beliefs that have no factual basis. </span>
I would say Recycling or using alternate power sources such as solar or wind