Consider the two-port network shown in the figure.

The admittance parameters, in siemens, are

- $y_{11}=2,\:y_{12}=-4,\:y_{21}=-4,\:y_{22}=2$
- $y_{11}=1,\:y_{12}=-2,\:y_{21}=-1,\:y_{22}=3$
- $y_{11}=2,\:y_{12}=-4,\:y_{21}=-1,\:y_{22}=2$
- $y_{11}=2,\:y_{12}=-4,\:y_{21}=-4,\:y_{22}=3$