Patti finds her husband Derek asleep in his recliner. She gently touches his shoulder and says, Derek, wake-up; the dog needs to go out. Derek abruptly responds, Patti, I am awake! Derek was most likely in
A: stage 1 N-REM.
B: stage 2 N-REM.
C: stage 3 or 4 N-REM.
D: REM sleep