To solve the given problem on parallel resonance circuits, we need to understand how current behaves in such circuits.

A parallel resonance circuit, also known as a tank circuit, typically involves a capacitor (\(C\)) and an inductor (\(L\)) connected in parallel. At resonance, the inductive reactance and capacitive reactance are equal in magnitude but opposite in phase, leading to the current through the inductor and capacitor being 180 degrees out of phase.

Here are the key points to consider:

• At resonance, the impedance of the circuit becomes very high, which minimizes the current in the source branch.
• The phase angle between the voltage across the circuit and the supply current is zero; however, the current will lead or lag the applied emf when considered across each component.
• Given the options, considering a phase angle of \(\pi\) implies a complete 180-degree phase shift, meaning the current could be perfectly anti-parallel to the voltage.

This leads us to the correct interpretation of the fourth option given:

leads or lags the emf by a phase angle of \(\pi\)

In conclusion, in a parallel resonance circuit, the individual currents may lead or lag the emf by a phase angle of \(\pi\), depending on which element (capacitor or inductor) you are examining. This is consistent with the characteristics of being resonant, as the parallel impedance reaches a maximum, and the reactive components perfectly cancel each other's effect over the full cycle.