A capacitor of capacity `C` is connected with a battery of potential `V` in parallel. The distance between its plates is reduced to half at one, assuming that the charge remains the same. Then to charge the capacitance upto the potential `V` again, the energy given by the battery will be
A. `CV^(2)//4`
B. `CV^(2)//2`
C. `2CV^(2)//4`
D. `CV^(2)`
