Concept:At resonance, the inductive reactance equals the capacitive reactance, so they cancel each other out.
Explanation:At the resonant frequency,
XL=XC.
Thus, the circuit behaves like a purely resistive circuit.
In a purely resistive circuit, there is no phase difference between voltage and current.
Therefore, the current is in phase with the supply voltage.
Answer:D. is in phase with the supply voltage