$A.$ $\left[ Fe ( CN )_6\right]^{3-}$;$B.$ $\left[ FeF _6\right]^{3-}$; $C.$ $\left[ CoF _6\right]^{3-}$; $D.$ $\left[ Cr (\text { oxalate })_3\right]^{3-}$; $E.$ $\left[ Ni ( CO )_4\right]$
નીચે આપેલા વિકલ્પોમાંથી સાચો જવાબ પસંદ કરો.
$(I)$ $\left[\mathrm{Cr}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right] \mathrm{Br}_{2}$
$(II)$ $ \mathrm{Na}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]$
$(III)$ $\mathrm{Na}_{3}\left[\mathrm{Fe}\left(\mathrm{C}_{2} \mathrm{O}_{4}\right)_{3}\right]\left(\Delta_{0}>\mathrm{P}\right)$
$(IV)$ $\left(\mathrm{Et}_{4} \mathrm{N}\right)_{2}\left[\mathrm{CoCl}_{4}\right]$