The most used "drug" is alcohol.
Cardiovascular system has to do with the heart, so anything to reduce the risk of that system (including the heart, bloodstream etc.) would be the answer for you. So just using Process of elimination:
A) Has to do with external exposure. <em>No</em><em />
B) Keeping hands clean <em>No</em><em />
C) Avoiding cigarette smoke <em>Yes</em>
D) Keeping your vaccinations up to date <em>No</em><em />
So your answer is C.
Explanation:
Humanistic psychology acknowledges that the mind is strongly influenced by determining forces in society and the unconscious, and emphasizes the conscious capacity of individuals to develop personal competence and self-respect.
