# Which of the following cyano complexes would exhibit the lowest value of paramagnetic behaviour

$(a)\;[Cr(CN)_6]^{-3}\qquad(b)\;[Mn(CN)_6]^{-3}\qquad(c)\;[Fe(CN)_6]^{-3}\qquad(d)\;[CO(CN)_6]^{-3}$

$[CO(CN)_6]^{-3}$ exhibits the lowest value of paramagnetic behaviour
Hence (d) is the correct answer.