Most of the Time,Shandra Has No Problems Sleeping Soundly

Most of the time,Shandra has no problems sleeping soundly.When things get hectic at work,however,she finds that she has trouble falling asleep and feeling rested when she wakes.Because Shandra feels even more tired when she is stressed,she thinks she should be sleeping better;however,we know that

A) stress can decrease sleep quality.
B) people who sleep during the day usually get more rest than those who sleep at night.
C) the human body is unable to manage stress of any kind,so Shandra needs more sleep than she can possibly get in a single day.
D) the stress in our lives has no effect on our sleep.