Indicate the complex/complex ion which did not show any geometrical isomerism:
\( \mathrm{[CoCl_2(en)_2]} \)
\( \mathrm{[Co(NH_3)_4Cl_2]^+} \)
\( \mathrm{[Co(NH_3)_3(NO_2)_3]} \)
\( \mathrm{[Co(CN)_5(NC)]^{3-}} \)