Concept:The summer solstice in the Northern Hemisphere is the day when the North Pole is tilted most directly toward the Sun.Explanation:On June 21, the Sun is overhead at the Tropic of Cancer.The Northern Hemisphere receives the most direct sunlight on this day.This gives the region its longest day and marks the beginning of summer.Hence, the summer solstice in the Northern Hemisphere occurs on June 21.Answer:B. June 21