What underlying concern does the man express about his sleep?

The man's underlying concern about his sleep is connected to his worries regarding unresolved problems. This indicates that his mind is preoccupied with issues that have not been settled, which can lead to restlessness and difficulty falling or staying asleep. Unresolved problems can create mental clutter, making it hard for people to relax and rest properly. This concern highlights how psychological factors, such as stress from unresolved conflicts or worries, can significantly impact one's ability to achieve restful sleep. Understanding this connection reinforces the importance of addressing personal issues or seeking resolutions to promote better sleep quality. The choice that highlights this relationship accurately reflects the man's state of mind in relation to his sleep challenges.