In the following circuit the current is in phase with the applied voltage. Therefore, the current in the circuit and the frequency of the source voltage respectively, are

A

$$\frac{V_i}{R}$$ and $$\frac{1}{2\pi\sqrt{LC}}$$

B

zero and $$\frac{1}{\sqrt{LC}}$$

C

$$\sqrt{\frac{C}{L}}\,V_i$$ and $$\frac{2}{\pi\sqrt{LC}}$$

D

$$\sqrt[4]{\frac{C}{LR^2}}$$ and $$\frac{2}{\sqrt{LC}}$$