Calculate the energy in the 2 F capacitor

Correct option is D

​$$\text{The energy stored in a capacitor is given by:} \\E = \frac{1}{2} C V^2 \\\text{Substitute } C = 2 \, \text{F} \text{ and } V = 4 \, \text{V:} \\E = \frac{1}{2} \times 2 \times 4^2 = 4 \, \text{J}$$​​