Which of the following best describes the non-REM (NREM) sleep stage?

The non-REM (NREM) sleep stage is indeed often described as a restful stage where the body engages in vital repair processes. During NREM sleep, particularly in its deeper stages, the body focuses on physical restoration, including muscle growth, tissue repair, and immune function. This phase is essential for overall health and well-being, facilitating recovery and maintenance of various bodily functions.

In contrast, the other options do not accurately reflect the characteristics of NREM sleep. For instance, the light stage of sleep with active dreaming pertains more to REM sleep, where vivid dreams commonly occur. Additionally, deep sleep associated with muscle atonia refers specifically to REM sleep, where the body experiences a temporary paralysis to prevent acting out dreams. Lastly, the distinct feature of rapid eye movement is exclusive to REM sleep, making it a characteristic that doesn’t apply to NREM sleep stages. Overall, option C provides the most accurate depiction of what occurs during non-REM sleep.