An air$-$filled parallel plate capacitor has round plates and carries a fixed amount of equal but oppositecharge on its plates. All the geometric parameters ofthe capacitor $($plate diameter and plate separation$)$are now halved.If the original energy stored in the capacitor was U$0,$ the new stored energy is:A$.$ U$0/8$ B $2$U$0$ C U$0$ D U$0/12$ E U$0/4$