What is the Prime Meridian?

The Prime Meridian is defined as a line of longitude at zero degrees, which is pivotal for the system of geographic coordinates used to determine locations on Earth. It serves as the starting reference point for measuring longitude. This line runs from the North Pole to the South Pole, passing through Greenwich, London.

Understanding the significance of the Prime Meridian is crucial in navigation and mapping, as it allows for a standardized way to determine east and west locations around the globe. By establishing this baseline, it facilitates the division of the Earth into the Eastern and Western Hemispheres, which are fundamental concepts in geography.

The other options don't correctly define the Prime Meridian: it is not a latitude line, nor is it associated with historical trade routes or geographical boundaries between continents. Instead, it plays a central role in the global coordinate system, making it essential for understanding longitude and navigation.