Answer: D. 2.5 V
Step-by-step explanation:
Electric potential of a point in space is a scalar magnitude that allows a measurement of the electric field at that point to be obtained through the electrostatic potential energy that a electric charge would acquire if it is placed at that point.
In other words, it is the work that an external force must carry out to bring a unit positive charge from the reference point to the point considered, against the electric force and at constant speed.
Being its unit of the International System is the Volt (V).
Hence, the correct option is D. 2.5 V