I would go with both A and B. But you might want to wait for a better answer cause I'm not too sure
Answer:
The chair will accelerate to the right.
Explanation:
As we know by Newton's Law that when some net unbalanced force is exerted on the system then it will accelerate in the direction of force and the equation is given as

now we know that 6 N force is exerted on the chair towards right
So here the chair will accelerate in the direction of net force
so correct answer is given as
The chair will accelerate to the right.
Total force = Frope - mg = 309-300
total force = ma
9 = 30a