$A$ parallel plate capacitor is charged and then disconnected from the source of potential difference. If the plates of the capacitor are then moved farther apart by the use of an insulated handle,which one of the following is true?

• A
  The charge on the capacitor increases.
• B
  The charge on the capacitor decreases.
• C
  The capacitance of the capacitor increases.
• D
  The potential difference across the plates increases.