Which of the Following Is Most Likely to Cause People

Which of the following is most likely to cause people to have difficulty falling asleep?

A) moving from the east coast to the west coast
B) becoming accustomed to going to bed early and then trying to shift to going to bed later
C) becoming accustomed to going to bed late and then trying to shift to going to bed earlier
D) living in a cave-like environment with no cues to time and going to sleep whenever they feel like it