An object is moving north. From only this information one can conclude (A) that there is a single force on the object directed north. (B) that there is a net force on the object directed north. (C) that there may be several forces on the object, but the largest must be directed north. (D) nothing about the forces on the object.

The correct option is (B) that there is a net force on the object directed north.There are many forces acting on the object from different direction. But since the object is moving in the north direction, therefore that there is a net force on the object directed north.From the above observation we conclude that, option (B) is correct.