The correct option is
D [Zn(gly)2](a).
[Pt(bn)2]2+ has square planar complex because of its
dsp2 hybridisation and hence, molecular plane is the plane of symmetry, it does not show optical isomerism.
(b). Cis form of
[CrCl2(en)2]+ is optically active, because the
en ligands are at adjacent position and are at different plane. Lack of plane of symmetry result in optical isomerism.
trans - form of this compound is optically inactive due to plane of symmetry.
(c). The complex ion
[Co(en)3]3+ is optically active due to the absence of plane of symmetry.
(d).
[Zn(gly)2] is a outer orbital complex due to its fully filled d-orbital so the hybridisation of the complex is
sp3 and it form tetrahedral complex.
Tetrahedrals have no plane of symmetry so it show optical isomerism. P