Suppose That There Are Two Forces Acting on a Barge

Multiple Choice

Suppose that there are two forces acting on a barge being towed along a river. One force is exerted due south by the river current and has a magnitude of 7 units (the exact nature of the force unit is unimportant) . The other force is exerted by a tugboat and has a magnitude of 11 units towards the north and 3 units towards the east. What is the net force acting on the barge?

A) 11 units towards the north, 4 units towards the east
B) 18 units towards the north, 3 units towards the east
C) 4 units towards the north, 3 units towards the east
D) 3 units towards the north, 4 units towards the east