Which of the following transition metal complexes is chiral and can exist as a pair of non-superimposable optical isomers?
![cis-[Co(en)2(H2O)2]3+ optical isomers](/_next/image?url=https%3A%2F%2Fassets.mathsgenie.co.uk%2Faqa-qb%2F405299a9-c7d0-4f1f-aa31-913f22da1170.png&w=3840&q=75)
cis−[Co(en)2(H2O)2]3+cis-[Co(\text{en})_2(\text{H}_2\text{O})_2]^{3+}cis−[Co(en)2(H2O)2]3+ (where en=H2NCH2CH2NH2\text{en} = \text{H}_2\text{NCH}_2\text{CH}_2\text{NH}_2en=H2NCH2CH2NH2)
trans−[Co(en)2(H2O)2]3+trans-[Co(\text{en})_2(\text{H}_2\text{O})_2]^{3+}trans−[Co(en)2(H2O)2]3+ (where en=H2NCH2CH2NH2\text{en} = \text{H}_2\text{NCH}_2\text{CH}_2\text{NH}_2en=H2NCH2CH2NH2)
trans−[Pt(NH3)2Cl2]trans-[Pt(\text{NH}_3)_2\text{Cl}_2]trans−[Pt(NH3)2Cl2]
[Fe(H2O)6]3+[Fe(\text{H}_2\text{O})_6]^{3+}[Fe(H2O)6]3+