Today is June 20th, and the latest solar term is () A. Equinox B. Summer solstice C. Autumn equinox D. Winter solstice.

Looking at the map, we can see that when the earth runs at point B on the map, it is the vernal equinox in the northern hemisphere, and the date is around 2 1 March, when the global day and night are equal in length; When the earth moves at point C in the figure, it is the summer solstice in the northern hemisphere, and the date is around June 22, when the day is the longest and the night is the shortest in the northern hemisphere; Today is June 20th, and the latest solar term is the summer solstice.

Therefore, choose: B.