Answer: The Prime Meridian
Step-by-step explanation:
There are imaginary lines that are drawn across the Earth from the North pole to South pole called lines of longitude. They help in the identification of locations around the world when used in conjunction with latitudes.
Lines of Longitude are measured in degrees with the middle line measuring 0°. This is the Prime Meridian and it passes through countries like the UK and Ghana. The Prime Meridian is the basis for the various time zones that we have on Earth with it representing the GMT.