A 800 Kg Mass Is Moving at 5

A 8.00 kg mass is moving at 5.00 m/s SOUTH and a 6.00 kg mass is moving at 7.00 m/s EAST. Find the velocity of the center of mass, letting (a) = the east-west component, and (b) = the north-south component.

A) a = +0.50 m/s, b = +3.00 m/s.
B) a = +3.00 m/s, b = +2.86 m/s.
C) a = −3.00 m/s, b = −3.00 m/s.
D) a = +3.00 m/s, b = −2.86 m/s.
E) a = +42.0 m/s, b = −40.0 m/s.