<prompt> Sleep spindle is seen in-REMStage 1 NREMStage 2 NREMStage 3 NREM  <response>: Ans is c i.e., Stage 2 NREM o Full awake and alert state - Beta rhythmo Awake, eye closed and mind wandering but with less attentiveness - Alpha - rhythmo Stage 1 NREM - Theta rhythmo Stage 2 NREM - Sleep spindles, K complexo Stage 3 4 NREM Deep sleep - Delta rhythmo REM sleep - Beta rhythm and sometimes also reappearance of alpha rhythm. 