The correct answer is: A. Northward
The first point of Aries is the vernal equinox, which is the day when the sun crosses the equator from south to north. This happens on March 20 or 21 in the Northern Hemisphere and on September 22 or 23 in the Southern Hemisphere.
After the vernal equinox, the sun moves northward in the sky. This means that the days get longer and the nights get shorter in the Northern Hemisphere. In the Southern Hemisphere, the opposite is true: the days get shorter and the nights get longer.
The vernal equinox is an important astronomical event because it marks the beginning of spring in the Northern Hemisphere and autumn in the Southern Hemisphere. It is also a time of celebration for many cultures around the world.
Option B is incorrect because the sun moves northward after the vernal equinox. Option C is incorrect because the sun moves from south to north of the equator at the vernal equinox. Option D is incorrect because the sun moves from north to south of the equator at the winter solstice.