Smokers of pipes or cigars run a distinctly lower risk to their health than do cigarette smokers. However, whereas cigarette smokers who quit smoking altogether sharply reduce their risk of smoking-related health problems, those who give up cigarettes and take up pipes or cigars remain in as much danger as before.
Which one of the following, if true, offers the best prospects for an explanation of why the two changes in smoking habits do not both result in reduced health risks?
(A) Smokers of pipes or cigars who quit smoking thereby reduce their risk of smoking-related health problems. - WRONG. Doesn't explain why cigarettes smokers don't reduce health risk.
(B) Cigarette smokers who quit smoking for a time and
who then resume cigarette smoking do not necessarily reduce their risk of smoking-related health problems. - WRONG. Doesn't explain why cigarettes smokers don't reduce health risk after switching to cigars or pipes.
(C) The kinds of illnesses that smokers run an increased risk of contracting
develop no earlier in cigarette smokers than they do in smokers of pipes or cigar. - WRONG. Doesn't explain why cigarettes smokers don't reduce health risk. Irrelevant at best.
(D) At any given period in their lives, virtually all smokers smoke either cigarettes exclusively or cigars exclusively or pipes exclusively, rather than alternating freely among various ways of smoking. - WRONG. Doesn't explain why cigarettes smokers don't reduce health risk. Irrelevant like C.
(E) People who switch from cigarette smoking to smoking pipes or cigars inhale
smoke in a way that those who have never smoked cigarettes do not. - CORRECT. "Those who have never smoked cigarettes" might be confusing. It can include people who smoked cigars or pipes but not cigarettes ever, not just people who never smoked.
Answer E.