Select the correct IUPAC name for $F{e_4}{[Fe{(CN)_6}]_3}$ :
A.Iron (III) hexacyanoferrate (II)
B.Iron (III) hexacyanoferrate (III)
C.Iron (III) hexacyanidoiron (III)
D.Iron (II) hexacyanidoiron (II)

Hint: Generally, the IUPAC nomenclature of the organic compound refers to the systematic approach taken for the nomenclature of the organic compound as per the recommendation of international union of pure and applied chemistry. Moreover, the naming of the compound is usually done by keeping in mind the rules of IUPAC nomenclature.

Complete step by step answer:
The international union of Pure and Applied chemistry is an international organization designed to address the problems or issues concerning the chemical sciences around the world. However, there are a set of rules given by IUPAC for the systematic nomenclature of the organic compounds.
Now, in the complex, iron which is outside the sphere is in +3 oxidation state while iron within the coordination sphere is in -2 oxidation state. So, it will be named as ferrate and the oxidation states are written in roman letters within the bracket and there is a cyanide group also present. So, the IUPAC name of the given compound is Iron (III) hexacyanoferrate (II).
Hence, option A is correct.

Note:However, the IUPAC guidelines are not always followed by chemists. This is because the compounds have very long and extremely tedious names. So, these compounds are assigned with trivial names. In such types of names, there is no particular set of rules. Moreover, the purpose of this system is to give unique names to each structure.