Answer:
D. Allow him to go around obstacles too difficult.
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.
you add cheese, yogurt, sardines, salmon, beans, almonds, and reduce intake of caffeine
