Which line of longitude passes through Greenwich, London?

• A. 90 degrees longitude
• B. 180 degrees longitude
• C. 0 degrees line of longitude
• D. 45 degrees longitude

Answer: (C)

Longitude is measured from a starting line that runs through Greenwich, London. The line that passes there is the 0 degree meridian, known as the Prime Meridian. It defines the reference point from which we measure how far east or west a location sits, with numbers increasing to 180 degrees toward the east and toward the west. The 0 degree line is the only one that goes through Greenwich, which is why it’s the correct choice. The other options correspond to different meridians that lie elsewhere on the globe, not through Greenwich. Greenwich’s role as the Prime Meridian is tied to historical definitions of time and navigation as well.