3. When a parallel plate capacitor is connected to a battery with voltage $V_0$, it gains a charge $Q_0$. It is then carefully removed from this battery, and a material of dielectric constant 2 is carefully inserted between its plates, filling the entire space between its plates. After this is done, what is the charge of this capacitor and voltage across this capacitor in terms of $Q_0$ and $V_0$, respectively?
(A) $\frac{1}{2}Q_0$, $\frac{1}{2}V_0$
(B) $Q_0$, $\frac{1}{2}V_0$
(C) $\frac{1}{2}Q_0$, $V_0$
(D) $2Q_0$, $V_0$
(E) $Q_0$, $2V_0$
