单选题 The efforts against adolescents' smoking doesn't have desirable effect mainly because ______.

A、 the anti-smoking advertisements are not convincing owing to their exaggeration
B、 the teenage smokers developed the habit of smoking out of the compulsory pressure from their schoolmates
C、 smoking is a relatively low-costing bad habit
D、 one can always get cigarettes in pubs when vending machines are removed

【正确答案】 B

【答案解析】四个选项文中均有涉及，但青少年吸烟最主要的一个原因是来自同龄人的压力“For the most part，they say，teens smoke because of peer pressure”，所以应该选B。