Which complex is likely to show optical isomerism?

(i) ${\left[C{o}^{III}{\left(N{H}_3\right)}_2{\left(en\right)}_2\right]}^{3+}$  exhibit geometrical isomerism, but trans form is optically inactive and cis form is optically active.
(ii) Both cis and trans forms of  ${\left[C{o}^{III}C{l}_2{\left(N{H}_3\right)}_4\right]}^{+}$ are optically inactive
(iii) ${\left[C{r}^{III}{\left(H_{2}O\right)}_6\right]}^{3+}$   does not exhibit both geometrical and optical isomerism