# A two terminal device is connected in a circuit and is found that it conducts when either forward biased or reverse biased and also operates both in AC and DC. The device is

$(a)\;\text{Diode } \\(b)\;\text{triode } \\(c)\;\text{LED } \\(d)\;\text{Resistor}$

Triode is a 3 terminal devices, Diode and LED work only on forward bias.
This device is a Resistor .
Hence d is the correct answer.