根据以下材料，回答题
Being Teenagers
It has never been easy to be a teenager， and it is particularly difficult today. The world expects us to be grown up but rarely treats us like adults; we are part of a society in which drugs are readily available but extremely dangerous; our education consists of examinations and more examinations.
Is it any wonder we struggle at times？
One of the biggest problems is that patents demand mature and intelligent behavior. from us， yet usually think of us as still being children. We help do a range of housework and care for sickly grandparents， but cannot watch adult movies on television. We are expected to show an interest in current affairs and get a part-time job to begin to support ourselves， but are not even allowed a say in where we go for the family holiday——never mind being allowed to holiday with our friends!
Outside the home， we have to make sure our dissatisfaction does not lead us to rebellion and to the dealers who are just waiting to sell us various drugs. Older generations had to come to terms with alcohol and cigarettes; that was easy， by comparison. We go to a club， to dance， then are faced with temptations （诱惑） ， peer pressures and our own desire to fit in with the crowd. There is always someone there with a designer drink， a designer smile and the latest designer drug to tempt us. Being a teenager has never been harder.
Of course; it has never been so hard in school either. We have so many examinations that it is difficult to keep track: SATs， GCSEs ...and the practice tests that accompany them.
Homework is never ending. No teacher seems aware of how much work the others are setting，and， anyway， they would not care， because they are all under orders to improve results or their own careers will suffer.
What is Paragraph 1 mainly about？ 查看材料

A. The tempting drugs that can be easily bought.
B. The changing world that teenagers have to adapt to.
C. School education that focuses merely on examinations.
D. Various problems that teenagers have to deal with.