in what direction is there a net force of 200?
A. Left
B.right
C.up
D. Down

Answer: B. Right
Explanation:
According to this Free Body Diagram we have:
[tex]\sum F_{y}=300 N - 300 N = 0 N[/tex]
[tex]\sum F_{x}=-200 N + 400 N = 200 N[/tex] (being the left negative and the right positive)
So, since the magnitude of the net force is positive its direction is to the right.