A $3$-bus power system network consists of 3 transmission lines. The bus admittance matrix of the uncompensated system is
$\begin{bmatrix}
-j6 &j3 &j4 \\
j3&-j7 &j5 \\
j4& j5 & -j8
\end{bmatrix}$ pu.
If the shunt capacitance of all transmission lines is $50\%$ compensated, the imaginary part of the $3^{rd}$ row $3^{rd}$ column element (in pu) of the bus admittance matrix after compensation is
- $−j7.0$
- $−j8.5$
- $−j7.5$
- $−j9.0$