IUPAC name of  ${\mathrm{K}}_4\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]$ is

A) Name cation first .
B) While naming counter ions prefixes like  di, tri, tetra should not be used.
C) While naming complex, ligand is named first with proper prefix.
D) ${\mathrm{CN}}^{–}$ is cyano (or) cyanido.
E) For anionic complex, the suffix –ate must be used after the name of metal ion
D) Oxidation number of central metal ion must be written as roman number in parenthesis
$\therefore$  Potassium  Hexacyanoferrate(II)
(or)
Potassium hexacyanidoferrate(II)