A Dielectric Is Inserted Between the Plates of an Isolated

A dielectric is inserted between the plates of an isolated parallel-plate capacitor that carries a charge Q. What happens to the potential energy stored in the capacitor?

A) The potential energy of the capacitor decreases.
B) The potential energy of the capacitor increases or decreases depending on the value of the dielectric constant of the capacitor.
C) The potential energy of the capacitor remains the same.
D) The potential energy of the capacitor increases.
E) More information is needed to answer the question.