Which of the following has an optical isomer?
(en=ethylenediamine) ?

Options

A. `[Zn(en)(NH_(3))_(2)]^(2+)`
B. `[Co(en)_(3)]^(3+)`
C. ` [Co (H_(2) O)_(4) (en)]^(3+)`
D. `[Zn(en)_(2)]^(2+)`

Answer

B

Explanation

Complex `[Co(en)_(3)]^(3+)` has no plane of symmetry and centre of symmetry that's why it is optically active