In the complex ion $\left[\mathrm{Fe}\right(\mathrm{EDTA}){]}^{-}$ the coordination number and oxidation state of central metal ion is:

${\mathrm{K}}_3\left[\mathrm{Fe}(\mathrm{CN}{)}_6\right]$ is:

$\left(\mathrm{a}\right)$ Potassium hexacyanoferrate $\left(\mathrm{II}\right)$.
$\left(\mathrm{b}\right)$ Potassium hexacyanoferrate $\left(\mathrm{III}\right)$.
$\left(\mathrm{c}\right)$ Potassium ferri-cyanide
$\left(\mathrm{d}\right)$ Hexacyano ferrate $\left(\mathrm{III}\right)$ potassium.

The correct answer is: