The point at which sun’s declination changes from north to south, is known as A. First point of Aeries B. First point of Libra C. Vernal Equinox D. Both (B) and (C) of the above

The correct answer is: D. Both (B) and (C) of the above.

The first point of Aries is the point in the sky where the Sun appears to cross the equator from south to north on the March equinox. It is also known as the vernal equinox. The first point of Libra is the point in the sky where the Sun appears to cross the equator from north to south on the September equinox. It is also known as the autumnal equinox.

The Sun’s declination is the angle between the Sun’s apparent position in the sky and the celestial equator. The Sun’s declination changes

throughout the year as the Earth orbits the Sun. At the vernal equinox, the Sun’s declination is 0 degrees. At the summer solstice, the Sun’s declination is 23.5 degrees north. At the autumnal equinox, the Sun’s declination is 0 degrees. At the winter solstice, the Sun’s declination is 23.5 degrees south.

The first point of Aries and the first point of Libra are the two points on the celestial equator where the Sun’s declination changes from north to south.