The Angular Frequency of a Certain RLC Series Circuit Is $\omega$

The angular frequency of a certain RLC series circuit is $\omega$ ₀. A source of sinusoidal emf, with angular frequency $\omega$ , is inserted into the circuit and $\omega$ is varied while the amplitude of the source is held constant. For which of the following values of $\omega$ is the amplitude of the current oscillations the greatest?

A) $\omega$ ₀/5
B) $\omega$ ₀/2
C) $\omega$ ₀
D) 2 $\omega$ ₀
E) None of them (they all produce the same current amplitude)