A pendulum of length L oscillates inside a box. A person picks up the box and gently shakes it vertically with frequency \omega and a fixed amplitude for a fixed time. To maximize the final amplitude of the pendulum, \omega should satisfy
Answer Choices
A. \omega=\sqrt{4 g / L}
B. \omega=\sqrt{2 g / L}
C. \omega=\sqrt{g / L}
D. \omega=\sqrt{g / 4 L}
E. there will be no significant effect on the pendulum amplitude for any value of \omega