Concept:The sun’s direct rays shift between the Tropic of Cancer and the Tropic of Capricorn over the year.Explanation:The Tropic of Capricorn is found at about 23.5∘ South.The sun is vertically overhead at this latitude during the December solstice.This event occurs around December 21st or 22nd each year.At that time, the Southern Hemisphere enjoys its longest day and shortest night.Therefore, from the given options, December 22nd is the correct date.Answer:D. December 22nd