问题：
[单选题] Text 4 When you go to bed,is it because you're tured or because you need to get up at a certain time and want to make sure you get enough sleep?Everyone has a chronotype,which is the sleep cycle that
A、the sleep cycle that body would naturally prefer
B、the time people would like to wake up
C、the bedtime people choose for themselves
D、how long people sleep everyday
参考答案：
A、the sleep cycle that body would naturally prefer
● 参考解析
