A worker who recently switched from day to swing shift has become less efficient and more irritable. He is also making more mistakes than he did on the day shift. The cause of this worker's problem is likely to be:

a. sleep disorders due to change in shift
b. excessive light on the awing shift
c. external desynchronization and excessive light
d. internal desynchronization.
My answer is C. Can some let me know if I chose the correct answer.

Yes, you are correct! The likely cause of the worker's problem is external desynchronization and excessive light, option C. When a worker switches from the day shift (typically during the daylight hours) to the swing shift (typically during the evening or night hours), their internal body clock can become desynchronized with the external environment, leading to various issues.

Excessive light during the swing shift can further disrupt the worker's internal body clock, making it difficult for them to adjust to the new schedule. This disruption can lead to sleep disorders, such as difficulty falling asleep or staying asleep during the daytime when the worker should be resting.

The worker's decreased efficiency, increased irritability, and increased mistakes are all common symptoms of sleep deprivation and disrupted circadian rhythm caused by the change in shift. These symptoms can significantly impact performance and well-being.

Therefore, option C, external desynchronization and excessive light, is likely the cause of the worker's problems.