The sun is directly overhead (vertical) at locations between the Tropic of Cancer (approximately 23.44° N) and the Tropic of Capricorn (approximately 23.44° S). Cities located south of the Tropic of Cancer will experience the sun directly overhead twice a year as the sun's apparent position moves between the equator and the Tropic of Cancer. Cities located exactly on the Tropic of Cancer will experience it once a year (on the summer solstice). Cities north of the Tropic of Cancer will never experience the sun directly overhead. Let's check the approximate latitudes: - Ahmedabad: ~23.03° N (South of Tropic of Cancer) - Delhi: ~28.7° N (North of Tropic of Cancer) - Nagpur: ~21.14° N (South of Tropic of Cancer) - Jaipur: ~26.92° N (North of Tropic of Cancer) Both Ahmedabad and Nagpur are located south of the Tropic of Cancer, meaning the sun will be vertical overhead twice a year. Delhi and Jaipur are north of the Tropic of Cancer, so the sun is never vertical overhead there. The question asks where the sun is vertical "at least once". Both Ahmedabad and Nagpur satisfy this condition (twice is "at least once"). However, typically in such MCQs, only one option is intended as correct. Assuming no error in the question/ options, and given that Ahmedabad is geographically very close to the Tropic of Cancer line (which passes slightly north of it), it's a common point of reference. Nagpur is also south. Both A and C technically fit. However, A is usually cited in such contexts when this specific set of options is presented.