Hi I can you help and baby me through this problem and show

Hi, I can you help and baby me through this problem and show step by step how to solve it thanks!

St ab= +120V S2 The network shown is assembled with uncharged capacitors X, Y, and Z, with Cx 5 uF Cy-8 F and CZ = 4 F, and open switches, S1 and S2. A potential difference Vab = +120 V is applied between points a and b. After the network is assembled, switch S1 is closed, but switch S2 is kept open. In the figure, the energy stored in capacitor X, in mJ, is closest to: A) 36 B) 0.60 C) 0.30 D) 72 E) 1.5

Solution

Answer is (D)

The energy of a capacitor = CV²/2= 72000J=72mJ

As the potential difference isb 120v.