① Earth revolution map (including solar terms, dates, direct points and phenomena) ② Direct points of the sun move between the Tropic of Cancer.

Point A is located on the Tropic of Capricorn, and the sun shines directly on the Tropic of Capricorn from the winter solstice. At this time, the days in the northern hemisphere are short and the nights are long, so A is correct.

C is located at latitude 10 S, where there is direct sunlight twice a year, so B is wrong;

Children's Day is closer to the summer solstice than Labor Day, so Children's Day has a long day, so C is wrong.

The model test is in April, and the earth runs between the vernal equinox and the summer solstice, that is, ② ③, so D is wrong.

So choose: a.