
Above system is equivalent to two capacitors in parallel,
So, capacitance of system is
$C_{ eq }=C_1+C_2=\frac{\varepsilon_0 A}{d}+\frac{\varepsilon_0 A}{d}=\frac{2 \varepsilon_0 A}{d}$
$(A)$ the charge on the upper plate of $C _1$ is $2 CV _0$
$(B)$ the charge on the upper plate of $C _1$ is $CV _0$
$(C)$ the charge on the upper plate of $C _2$ is $0$
$(D)$ the charge on the upper plate of $C _2$ is $- CV _0$


