Which is the correct explanation for 120°W longitude?

Aall positions along a circle that runs perpendicular to the equator and 120° west of the prime meridian

Ball positions along a circle that runs perpendicular to the equator and 120° east of the prime meridian

Call positions along a circle that runs parallel to the prime meridian and 120° east of the equator

Dall positions along a circle that runs perpendicular to the prime meridian and 120° west of the equator