This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S., Subject name: Medicine
[{'content': 'Sleep apnea syndromeFor above situations, select the most likely sleep disturbance. \nSelect and explain. \nA. sleep more than younger adults, B. increased arousals during the night, C. increased slow-wave sleep, D. most common cause of excessive daytime sleepiness in the elderly', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Sleep apnea syndrome is the most common cause of daytime sleepiness in the elderly. The prevalence (at least in sleep disorder centers) increases with advancing age. Narcolepsy (usually having started earlier in life) and periodic limb movement disorder (restless legs) are other common causes of excessive daytime sleepiness.', 'role': 'assistant'}]