Choice D and choice E.
Work Step by Step
The capacitance is determined by geometry (the shape of the capacitor plates and their separation distance), as well as the material between the plates (the dielectric). Capacitance is defined as the ratio of the charge on the plates to the potential difference between the plates. Doubling the charge will double the potential difference and change the energy stored. But the capacitance, the ratio of Q/V, remains the same.