Courtney believes that pulling regular all-nighters is an important part of being a college student ...

Courtney believes that pulling regular all-nighters is an important part of being a college student and she frequently goes all night without any sleep at all. Given what you know about sleep cycles and sleep deprivation, what else can you assume about Courtney?
 
  a. She probably is just one of those people who doesn't need much sleep.
 b. She is a conscientious student who probably has a very high grade point average
 c. She probably has a lower grade point average than most of her classmates and often feels depressed.
 d. She has probably maintained this same pattern of sleeping since childhood.