A natural supplement that can enhance sleep for many people is:.

Choice A rationale:

Sleeping with the window open for fresh air may not be the best solution in this scenario. While fresh air can be beneficial for sleep, it might not effectively block out the noise from the freeway and the nearby apartment complex. Furthermore, depending on the climate and location, having the window open might lead to discomfort or temperature-related issues.

Choice B rationale:

Performing exercise at bedtime is not a recommended solution for someone experiencing difficulty sleeping due to external noise. Exercise before bedtime can increase alertness and make it even more challenging to fall asleep, especially if it's vigorous exercise. It may exacerbate the problem rather than alleviate it.

Choice C rationale:

Having a couple of drinks at bedtime is not a suitable solution for sleep problems. Alcohol can disrupt sleep patterns and lead to poor-quality sleep. It may help the patient fall asleep initially but can lead to frequent awakenings and a less restful night's sleep.

Choice D rationale:

The correct choice is to wear soft earplugs for sleep. Soft earplugs can effectively reduce or block out external noise, providing a quieter sleep environment. This is a practical and safe solution to address the noise issue in the patient's apartment complex. It promotes better sleep quality without any negative side effects.

Choice A rationale:

Excessive NREM sleep does not cause periodic pauses in breathing. NREM (Non-Rapid Eye Movement) sleep consists of stages 1 through 4 and is characterized by a decrease in physiological activity, including a decrease in muscle tone. There is no direct association with breathing interruptions in NREM sleep.

Choice B rationale:

Insomnia is a sleep disorder characterized by difficulty falling asleep or staying asleep, but it does not involve periodic pauses in breathing. It is unrelated to the symptoms described in the question.

Choice C rationale:

Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness and sudden episodes of muscle weakness (cataplexy). It is not associated with periodic pauses in breathing, as described in the question.

Choice D rationale:

Sleep apnea is the correct answer. Sleep apnea is a sleep disorder characterized by repeated episodes of paused or shallow breathing during sleep. The patient may stop breathing for brief periods, then start breathing again. This pattern is consistent with the symptoms described in the question. Sleep apnea can have serious health implications and is important to recognize and address.