Please choose the correct ending to complete the given sentence: Health: [header] How to look refreshed when you wake up [title] Let in natural light. [step] Sunlight, or an artificial alternative, helps your body accept the awakening. Not only will you wake up easier, but you'll reset your body's clock, feel better rested, and improve your mood.

Ending1: [title] Do some exercise first thing in the morning. [step] Exercise increases body temperature and releases endorphins that help you awaken. Ending2: [substeps] Set an alarm and let it go off at sometime in the day. Studies have shown that people who select natural sunlight reduce their risk of developing sun-related disorders, such as cirrhosis or cancer. Ending3: [substeps] Get in the habit of letting in natural light in the morning. Whether you're seeing a movie, taking a walk in the park, or watching a new show, sunlight will keep you energized. Ending4: [substeps] You don't have to spend every waking moment of the day in the sun. Window exposure seems to be the only positive stimulant for most people.

Answer format: ending1/ending2/ending3/ending4