What causes Earth's day and night?

• A. Revolution
• B. Rotation
• C. Tilt
• D. Moon phase

Answer: (B)

Day and night come from Earth's rotation on its axis. The planet spins once roughly every 24 hours, so as the surface turns, different areas move into and out of the Sun’s light. When your location is facing the Sun, you experience day; as the place turns away, it becomes night. The tilt of Earth’s axis mainly affects seasons and the angle of sunlight, which changes how long days last at different times of year and at different latitudes, but the basic day-night cycle itself is due to rotation. The other ideas—revolution around the Sun, axial tilt, or the Moon’s phase—shape seasons, year length, or Moon visibility, not the daily cycle of day and night.