The Average Power Input to a Series Alternating Current Circuit

Multiple Choice

The average power input to a series alternating current circuit is minimum when

A) there are only a resistor and capacitor in the circuit.
B) there are only a resistor and inductor in the circuit.
C) there is only a resistor in the circuit.
D) X_L = X_C and the circuit contains a resistor, an inductor and a capacitor.
E) there is only a capacitor in the circuit.