June 21st, often referred to as the summer solstice, is the longest day of the year in the Northern Hemisphere. During this time, the Earth`s axis is tilted towards the sun at 23.5°, which is its maximum tilt.

Option-1 is correct because on this day, the sun does not set below the horizon at the Arctic Circle, but remains visible for the entire 24 hours.

Option-2 is incorrect due to the Earth`s axial tilt on June 21st, the sun will not remain above the horizon all day at the Antarctic Circle as it`s winter there.

Option-3 is wrong because the sun doesn`t shine vertically overhead at noon on the Equator but at the Tropic of Cancer on this day.

Option-4 is also incorrect because on June 21st, the sun shines vertically overhead at the Tropic of Cancer, not the Tropic of Capricorn as mentioned in the option.