Final answer:
Electric potential is highest A. near a positive charge because potential is positive around such charges and electric fields emanate away from them, attracting positive charges to regions of higher potential.
Step-by-step explanation:
The electric potential has the highest positive value when you look near a positive charge. This is because electric potential is directly related to the presence of charge, and potential is always positive around positive charges. In the context of electric fields and potentials, the direction of the electric field is away from positive charges and toward negative charges. Moreover, if you examine an electric potential map, such as those provided in reference figures, you'll see that electric potential is higher (more positive) near the positive charge and lower (more negative) near a negative charge.
Furthermore, a positive charge would be attracted from a larger distance where the potential is lower than near the charge, which means that the positive potential gradient attracts positive charges towards higher potentials, as we would expect given that like charges repel and opposite charges attract.