The magnetic variation at a location is the angular difference between the true North and the magnetic North at that location. To determine the magnetic variation, we need to subtract the course with respect to the true North from the course with respect to the magnetic North.
Magnetic Variation = Course with respect to Magnetic North - Course with respect to True North
Magnetic Variation = 122 degrees - 120 degrees = 2 degrees
Therefore, the magnetic variation at this location is 2 degrees.