## **Core Concept**
The question tests knowledge of sleep disorders, specifically those that occur during the night and involve episodes of fear or terror. The key detail here is the lack of memory for the episode, which helps differentiate it from other conditions like nightmares.

## **Why the Correct Answer is Right**
The correct answer, **C. Night Terrors (Sleep Terrors)**, is a type of sleep disorder that occurs during deep sleep (slow-wave sleep), typically in children. During an episode, the child may sit up, scream, and show signs of extreme fear or terror. A key characteristic is that the child usually does not remember the episode in the morning. Night terrors are associated with **incomplete arousal from slow-wave sleep**, which explains the child being in a state of fear but not being conscious or able to recall the event.

## **Why Each Wrong Option is Incorrect**
- **Option A: Nightmares** - These occur during REM sleep and are typically remembered by the child. Nightmares can cause fear and distress but usually happen in the second half of the night, and the child can recall the content.
- **Option B: Sleep Walking (Somnambulism)** - While sleep walking also occurs during deep sleep and the individual may perform complex behaviors without conscious awareness, it does not specifically involve episodes of terror or fear.
- **Option D: Restless Leg Syndrome** - This condition involves an uncomfortable sensation in the legs and an irresistible urge to move them, which is not related to episodes of terror or fear during sleep.

## **Clinical Pearl / High-Yield Fact**
A memorable point for exams is that **night terrors** are more common in children and are associated with **slow-wave sleep**, usually occurring in the first third of the night. Unlike nightmares, children do not recall the episodes, making it a distinct clinical entity.

## **Correct Answer: C. Night Terrors**