Failed to connect to MySQL: Access denied for user 'examnext_online'@'localhost' (using password: YES) In which of the following pairs both the complenes show optical isomerism ? - Sarthaks eConnect

In which of the following pairs both the complenes show optical isomerism ?

`cis-[Cr(C_2O_4)_2Cl_2]_3–, ci–[Co(NH_3)_4Cl]`

`[PtCl(dien)]Cl, [NiCl_2Br_2]^(2–)`

`[Co(NO_3)_3(NH_3)_3], cis—[Pt(en)_2Cl_2]`

`[Co(en)_3]Cl_3, cis—[Co(en)_2Cl_2]Cl`