If you adjusted the frequency to be lower than the resonant frequency, would the voltage have been leading ahead of or lagging behind the current? Explain

current will lead the voltage

Explanation:

From the bellow figure we can see the plot between the frequency and impedance

From the figure it is clear that when the frequency is less than the resonance frequency then the impedance decreases as the frequency increases it is possible only when impedance is capacitive in nature.

As the impedance is capacitive in nature so current will lead than the voltage