Right choice is (b) 0
To explain: A circuit which contains only inductance is called a pure inductive circuit and a circuit containing only a pure capacitor is known as a pure capacitive circuit. In a pure inductive circuit or a pure capacitive circuit, the current is lagging or ahead by 90 degrees from the voltage. The power factor is the cosine of the angle between the voltage and the current. Therefore:
Φ = \(\frac {\pi}{2}\) ➔ Power factor (cos\(\frac {\pi}{2}\))=0