Which compound configurational amplifiers gives increase in input impedance and equal decrease in output impedance ?

Which among the following compound configurational amplifiers gives tremendous increase in input impedance and equal decrease in output impedance ?

a. Cascade Amplifiers
b. Darlington Amplifier
c. Voltage Amplifier
d. Push - pull Amplifier

Correct Answer : b. Darlington Amplifier

Explanation :

Two emitters are cascaded in Darlington pair configuration whose overall gain approves to be unity, which is a major advantage of it as compared to other compound amplifiers.