The correct answer is: C. Minimum
At series resonance, the inductive reactance and capacitive reactance cancel each other out, leaving only the resistance in the circuit. This means that the impedance of the circuit is at its minimum value.
Inductive reactance is given by the formula $X_L = 2\pi f L$, where $f$ is the frequency and $L$ is the inductance. Capacitive reactance is given by the formula $X_C = \frac{1}{2\pi f C}$, where $f$ is the frequency and $C$ is the capacitance.
At resonance, the frequency is such that $X_L = X_C$. This means that the inductive reactance and capacitive reactance cancel each other out, leaving only the resistance in the circuit. This means that the impedance of the circuit is at its minimum value.
Option A is incorrect because the impedance of the circuit is not zero at resonance.
Option B is incorrect because the impedance of the circuit is not maximum at resonance.
Option D is incorrect because the impedance of the circuit is not none of the above at resonance.