Suppose a parallel plate capacitor (with capacitance C0) is fully charged (to a value Q0) by a battery

Suppose a parallel plate capacitor (with capacitance C0) is fully charged (to a value Q0) by a battery. The battery (which supplies a potential difference of V0) stays connected to the capacitor. If the plates of the capacitor are then moved closer together (the separation distance d b/w the plates is halved), describe QUANTITATIVELY what happens to:

a). the capacitance of the capacitors

b). the potential difference b/w the plates

c). the energy stored in the capacitor

d). the charge on the plates.