With $10$ V dc connected at port A in the linear nonreciprocal two-port network shown below, the following were observed:
- $1 \: \Omega$ connected at port B draws a current of $3$ A
- $2.5 \: \Omega$ connected at port B draws a current of $2$ A
With $10$ V dc connected at port A, the current drawn by $7 \: \Omega$ connected at port B is
- $3/7$ A
- $5/7$ A
- $1$ A
- $9/7$ A