The author emphasizes that sleep is not just rest, but a proactive activity crucial for health and performance, and therefore should be prioritized. The correct answer summarizes this main point.
The other options are incorrect for the following reasons:
- 'It is important to sleep deeply even for a short time.': The author advocates for securing time for sleep, not finding ways to sleep less.
- 'Modern people are demanding more rest.': The text focuses on the importance of prioritizing sleep, not analyzing people's desire for rest.
- 'One should reduce hobby time rather than work time to sleep.': The passage does not specify what activities should be cut to make time for sleep.