Answer:
C. Spending time outside during the day.
Exposure to natural light during the day can help regulate your sleep schedule by affecting the release of melatonin, a hormone that regulates sleep. Being outside in natural light during the day can help keep your circadian rhythm in sync, making it easier to fall asleep at night. While watching television or reading from electronic devices before bed can keep you up and make it harder to fall asleep, closing curtains after you wake up can help keep the bedroom dark and promote sleep.