Answer:
d. moving at

Step-by-step explanation:
We can solve the problem by applying Newton's second law:
(1)
where
F is the net force on the object
m is the mass of the object
a is its acceleration
Here we are only interested in the motion of the object along the horizontal direction. There are two forces acting on the object in this direction:
- The force
, pushing to the right, with magnitude 8.4 N
- The force
, pulling to the left, with magnitude 2.2 N
So, we can rewrite (1) as

Where:

And solving for a, we find the acceleration:

and the direction is the same as the net force, so to the right.