A person who smokes 1.5 packes daily gets 300 hits of nicotine to the brain each day. One cigarette has an average 10 nicotine in it. If one and a half pack has 30 sticks of cigarette. Nicotine is very very dangerous to a man's health. IT causes several types of caner. But the answer to your question is letter C - 300.
Reusing or sharing needles, really anything that can be spread through blood and drugs.. i hope this helps and sorry its so brief.
I think your answer for this question is D . I may be wrong ... but I think it's D