Answer:
Stage 2 N-REM
Step-by-step explanation:
as there is different stages of sleeping process and in stage 2 of Non -rapid eye movement sleep person eye movement is stop, heart beat and brain waves become slow. Person become less conscious about surrounding activities. It is light sleep and occur between wakefulness and deep sleep . So in this example Duke is in Stage 2 , in which he is light sleep but his roommate entrance awakened him.