An airplane is maintaining an air velocity of 200.0 km/h [30.0° north of east] in the face of a crosswind that is blowing 60.0 km/h [30.0° north of west]. Calculate the ground velocity of the plane.

A) 200.0 km/h [30.0° north of east]
B) 240.0 km/h [30.0° north of west]
C) 240.0 km/h [30.0° east of north]
D) 223.6 km/h [30.0° east of north]