Correct Answer: 21 March and 23 September

Solution : The correct answer is 21 March and 23 September.

The Sun is directly above Earth's equator during the equinoxes, two periods each year when neither pole faces the Sun. The equinoxes typically occur around March 21 and September 23. On March 21, the Northern Hemisphere experiences the spring or vernal equinox, while the Southern Hemisphere has the autumnal equinox. During these times, day and night are approximately equal in length.