Circuit Theorems in AC Analysis - Engineering

Q1:

The two basic components of a Thevenin equivalent ac circuit are

A the equivalent voltage source and the equivalent series impedance

B the equivalent voltage source and the equivalent series resistance

C the equivalent voltage source and the equivalent parallel impedance

D the equivalent voltage source and the equivalent parallel resistance

ANS:A - the equivalent voltage source and the equivalent series impedance

We calculate only Thevenin voltage and Thevenin resistance, so how it can be possible?

It should be resistance in series with voltage.