An LC circuit a $20\;mH$ inductor and a $50 \mu F$ capacitor with an initial charge of $10\;mc$ The resistance of the circuit is negligible. Let the instant the circuit is closed be $t=0$, What is the natural frequency of the circuit ?

Question

$\begin{array}{1 1} 15.91\;Hz \\ 1.591\;Hz \\ 159.1\;Hz \\ none\;of\;the\;above \end{array}$