In determining short circuit impedance parameters, among V1, V2, I1, I2, which of the following are independent variables?

In determining short circuit impedance parameters, among V1, V2, I1, I

1.	In determining short circuit impedance parameters, among V1, V2, I1, I2, which of the following are independent variables?
A.	I<sub>1</sub> and V<sub>2</sub>
B.	V<sub>1</sub> and I<sub>2</sub>
C.	I<sub>1</sub> and I<sub>2</sub>
D.	V<sub>1</sub> and V<sub>2</sub>
Answer» E.