Answer:
D
Explanation:
a neutron does not have a positive nor negative charge it remains neutral
The electrostatic potential energy, U, of one point charge q at position d in the presence of an electric field E is defined as the negative of the work W done by the electrostatic force to bring it from the reference position d to that position

Thus, to double the electric potential energy U we need to reduce the distance of separation by half (1/2) because they are inversely proportion
True !! Hope I helped you out a bit!