With $\text{10 V}$ dc connected at port $\text{A}$ in the linear nonreciprocal two-port network shown below, the following were observed:
- $\text1\;\Omega$ connected at port $\text{B}$ draws a current of $\text{3 A}$
- $\text2.5\;\Omega$ connected at port $\text{B}$ draws a current of $\text{2 A}$
For the same network, with $\text{6 V}$ dc connected at port $\text{A},$ $\text{1}\;\Omega$ connected at port $\text{B}$ draws $\frac{7}{3}\;\text{A}$. If $\text{8 V}$ dc connected to port $\text{A}$, the open circuit voltage at port $\text{B}$ is
- $\text{6 V}$
- $\text{7 V}$
- $\text{8 V}$
- $\text{9 V}$