Concept:The tilt of the Earth causes seasonal changes in the position of the overhead sun.Explanation:On 22nd December, the sun is overhead at the Tropic of Capricorn (23.5∘ S).At this time, the North Pole is tilted away from the sun.Thus, the Northern Hemisphere receives less direct sunlight and shorter daylight hours.This marks the official beginning of winter in the Northern Hemisphere.Therefore, the Northern Hemisphere experiences the winter solstice on this date.Answer:C. winter solstice