Which line divides the Earth into eastern and western hemispheres?

• A. Prime Meridian
• B. Equator
• C. Latitude line
• D. Longitude line

Answer: (A)

The boundary between eastern and western halves of the globe is set by the zero-degree longitude line, the Prime Meridian. It runs from the North Pole to the South Pole and passes through Greenwich, dividing longitudes east and west. Locations east of this line have east longitude, while those west have west longitude. The equator, by contrast, splits the planet into northern and southern hemispheres. A latitude line describes positions north or south of the equator, not the east–west boundary. Lines of longitude exist all around the globe, but the specific line that marks the division between eastern and western hemispheres is the Prime Meridian.