b
At steady state, capacitor behaves as an open circuit and current flows in circuit as shown in the diagram.

\( \mathrm{R}_{\text {eq }}=9 \Omega \)

\( \mathrm{i}=\frac{9 \mathrm{~V}}{9 \Omega}=1 \mathrm{~A} \)

\( \Delta \mathrm{V}_{6 \Omega}=1 \times 6=6 \mathrm{~V} \)

\( \mathrm{~V}_{\mathrm{A}}=3 \mathrm{~V}\)

So, potential difference across \(6 \mu \mathrm{F}\) is \(6 \mathrm{~V}\).

Hence

\(Q =C \Delta V \)

\( =6 \times 6 \times 10^{-6} \mathrm{C} \)

\( =36 \mu \mathrm{C}\)