Which one of the following has largest number of isomers?

Options

A. `[Ru(NH_(3))_(4)Cl_(2)]^(+)`
B. `[Co(en)_(2)Cl_(2)]^(+)`
C. `[Ir(PR_(3))_(2)H(CO)]^(2+)`
D. `[Co(NH_(3))_(5)Cl]^(2+)`

Answer

B

Explanation

All given compounds have cis and trans isomers but only cis-isomer of (b) will also have optical isomers (d and l) due to presence of symmetrical didentate, en.