Roy Was an Interstate Truck Driver

Multiple Choice

Roy was an interstate truck driver.He had been driving for the past 12 years, and most of his trips were between 11:00 p.m.and 7:00 a.m.Roy used to take irregular naps during the day, and also made time for other personal activities.However, overtime, he felt fatigued and decided to quit.After years of driving during the night, and sleeping for a few hours during the day, Roy is having trouble sleeping at night.Which of the following is a likely cause for Roy's condition?

A) Alzheimer's
B) Stress
C) Reduced blood pressure
D) Chronic insomnia