Final answer:
In patients over 65 years of age, there is a decrease in the percentage of deep N3 sleep, also known as slow-wave sleep.
Step-by-step explanation:
The correct answer is A. Lower percentage of N3 sleep. In patients over 65 years of age, there is a decrease in the percentage of deep N3 sleep, also known as slow-wave sleep. This stage of sleep is characterized by low frequency, high amplitude delta waves. The other changes in sleep architecture that are noted in patients over 65 years of age include: less total REM sleep, fewer REM episodes, increased awakening after sleep onset, and shorter REM episodes.