Answer & Explanation
D) All of the above
The 180th meridian or antimeridian is the meridian 180° east or west of the Prime Meridian, with which it forms a great circle dividing the earth into the Western and Eastern Hemispheres.
It is common to both east longitude and west longitude.
It is used as the basis for the International Date Line because it mostly passes through the open waters of the Pacific Ocean. However, the meridian passes through Russia and Fiji as well as Antarctica.