Final answer:
The work done to move a charged object in an electric field is converted into potential energy, which can later be converted into kinetic energy if the charge is allowed to move through the electric field.
Step-by-step explanation:
When you do work to move a charged object in an electric field, the work goes into changing the electric potential energy of the object. The work done on the charge moves it to a position where it can do an equal amount of work by virtue of its position in the field. If the charge is free to move, this electric potential energy can be converted into kinetic energy if it starts moving, much as a mass released in a gravitational field turns its potential energy into kinetic energy. However, if the charge is moved such that it doesn't start moving, the energy remains in the form of potential energy.
Specifically, when work is done against the electric field to move a charge (for example, from a lower potential to a higher potential), this work is stored as electric potential energy within the system. This potential energy can be recovered as work when the charge is allowed to move back through the electric field. Thus, the correct option is that the work done on a charged object in an electric field is converted into potential energy.