Answer:
The energy stored in capacitor B is four times the energy stored in capacitor A
Explanation:
First let the write-out the formula for the energy stored in a capacitor in-terms of the capacitance(C)and the voltage(V)

For capacitor A charged to a voltage of V, The energy stored is

and for capacitor B, we have ![\\W_{B}=\frac{1}{2}C[2V]^{2}\\](https://tex.z-dn.net/?f=%5C%5CW_%7BB%7D%3D%5Cfrac%7B1%7D%7B2%7DC%5B2V%5D%5E%7B2%7D%5C%5C)

From the energy stored in Capacitor A we can arrive at

if we substitute this value into the energy for capacitor B we arrive at

Hence we can conclude that the energy stored in capacitor B is four times the energy stored in capacitor A