Chọn C
Ta có: \(z^{4} -4z^{3} +14z^{2} -36z+45=0\)
\(\begin{array}{l} {\Leftrightarrow z^{4} -4z^{3} +5z^{2} +9z^{2} -36z+45=0} \\ {\Leftrightarrow z^{2} \left(z^{2} -4z+5\right)+9\left(z^{2} -4z+5\right)=0} \\ {\Leftrightarrow \left(z^{2} +9\right)\left(z^{2} -4z+5\right)=0} \\ {\Leftrightarrow \left[\begin{array}{l} {z^{2} +9=0} \\ {z^{2} -4z+5=0} \end{array}\right. \Leftrightarrow \left[\begin{array}{l} {z=3i} \\ {z=-3i} \\ {z=2+i} \\ {z=2-i} \end{array}\right. .} \end{array}\)