A meridian is

A.The circle of the earth passing through the poles and a point on the Earth’s surface
B.The distance between the Earth and the Moon
C.The axis around circle of the earth away from the equator towards the poles
D.The latitudinal circle of the earth away from the equator towards the poles

On 21st June, the sun

A.Does not sink below the horizon at the Antarctic circle
B.Does not sink below the horizon at the Arctic circle
C.Shines vertically overhead on the tropic of Cancer
D.Shines vertically overhead on the equator