Answer:
W = 2.74 J
Explanation:
The work done by the charge on the origin to the moving charge is equal to the difference in the potential energy of the charges.
This is the electrostatic equivalent of the work-energy theorem.

where the potential energy is defined as follows

Let's first calculate the distance 'r' for both positions.

Now, we can calculate the potential energies for both positions.

Finally, the total work done on the moving particle can be calculated.

You just multiply these two numbers, it's 1250J
A is pulling the block straight down toward the center of the Earth, no matter what the slope of the plane may be. A is the force of gravity.
The directions of B and C both depend on the slope of the plane.
B is a force that's parallel to the plane, pulling the block UP the plane. B is the force of friction.
C is a force perpendicular to the plane, preventing the block from falling down through the plane. C is the normal force.