What is the most probable reason for some rich people to use a device

What is the most probable reason for some rich people to use a device to record their patterns?

They have trouble falling asleep.

They want to get sufficient sleep.

They are involved in a sleep research.

They want to go to bed on regular hours.

答案及解析：本题考查细节理解。本题问的是富有的人使用设备来记录他们的睡眠模式的原因。由rich people以及device定位到最后一段第一句，定位句只说到了记录的事实，而非其原因。看到定位句的下一句“And people who elect to track22 / 22 their sleep may try to get more sleep than the average person”，记录睡眠的人是想要得到比普通人更多的睡眠，综上，B选项正确。故正确答案为B项。