Answer:
NREM-3
Explanation:
NREM-3 is most commonly known as 'Deep Sleep' .In this stage of sleep, you're at the hardest point to be waken up, and you will feel groggy /disoriented if you're forced to wake up in this state.
During this state, your brain consist of long and slow delta waves (which is not exist in other stage) , indicating that there are very little activity in your brain and your brain is expriencing a restorative mode.
