Which of the following compounds shows optical isomerism?

Which of the following compound shows optical isomerism?

Which of the following compounds show optical isomerism? I. cis -[Co(NH_(3))_(4) Cl_(2)]^(+) II. Trans - [Co(en)_(2) Cl_(2)]^(+) III. Cis - [Co(en)_(2) cl_(2)]^(+) IV. [Co(en)_(3)]^(3+) Choose the correct answer form the codes given below.

Which of the following compounds show optical isomerism ? (i) Cis-[Co(NH_3)_4Cl_2]^+ (ii) Trans-[Co(en)_2Cl_2]^+ (iii) Cis-[Co(en)_2Cl_2]^+ (iv) [Co(en)_3]^(3+) Choose the correct answer codes given below.

Which of the following compound show optical isomerism?

Which of the following compound show optical isomerism?