That would be reflection.
Refraction is the change in direction of a wave.
Diffraction is the bending of a wave around a barrier.
Answer:
-0.045 N, they will attract each other
Explanation:
The strength of the electrostatic force exerted on a charge is given by

where
q is the magnitude of the charge
E is the electric field magnitude
In this problem,

(negative because inward)
So the strength of the electrostatic force is

Moreover, the charge will be attracted towards the source of the electric field. In fact, the text says that the electric field points inward: this means that the source charge is negative, so the other charge (which is positive) is attracted towards it.
Understand, feel about, and behave toward seems the most likely