A air traffic controllers are frequently changing shifts and such irregular routine disrupts their biological rhythm.
B air traffic controllers are generally fatigued because they arrive home late and want to catch up with family news.
C regular sleep periods at the same time on all days of the week are mandatory.
D adjusting to varied working hours is like playing a game to catch up on leisure time.
E dark rooms and monotonous working routines can significantly alter our internal clocks.