Steroids promote the growth of muscle
the answer is C. distinguish himself from radicals.
It's easier to understand the difference when you treat them as separate entities. Mental health is about mental wellness - we all have mental health. Mental illness is when someone is diagnosed with a mental disorder.
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.
