The bus admittance matrix of a three-bus three-line system is $Y=j \begin{bmatrix} -13 & 10 & 5 \\ 10 & -18 & 10 \\ 5 & 10 & -13 \end{bmatrix}$ If each transmission line between the two buses is represented by an equivalent $\pi$-network, the magnitude of the shunt susceptance of the line connecting bus $1$ and $2$ is
- $4$
- $2$
- $1$
- $0$