Which direction does the prime meridian represent in terms of longitude?

The prime meridian serves as the foundational line of longitude from which all other longitudes are measured. It is established at 0 degrees longitude and runs vertically through Greenwich, London. The concept of longitude refers to the geographic coordinate system which measures distances east and west of this prime meridian.

When we refer to east and west in terms of longitude, we are indicating the measurements that occur in both directions from the prime meridian: eastward longitudes are measured up to 180 degrees, and westward longitudes are similarly measured up to 180 degrees as well. Therefore, the prime meridian itself signifies the transition between the eastern and western hemispheres, making it indicative of both directions.

The options that suggest only one direction (eastward or westward) are limited in scope, as they fail to encompass the complete understanding of how longitude operates relative to the prime meridian. Additionally, the notion of north and south relates to latitude, not longitude, further reinforcing why the answer indicating east and west is the most accurate.