Which of the following complex does not show geometrical isomerism?

${\left[\mathrm{Cr}(\mathrm{en}{)}_3\right]}^{3+}$ will have 2 optical isomers but have no geometrical isomers. The complex ${\left[\mathrm{Cr}(\mathrm{en}{)}_3\right]}^{3+}$ contains no element of symmetry.

 This complex optically active and resolved in d and l isomers.

Hence correct option is C.