The correct option for the finest quality of iron is (ii) Magnetite
Magnetite- Iron ore
Haematite, Magnetite, Siderite, Iron pyrites are the ores of the metal Iron. Among all the ores of Ferrous (Iron) magnetite is the finest quality of iron ore. Magnetite is the finest iron ore with a very high content of iron, up to 70%. It has excellent magnetic qualities. Fe3O4 is the chemical formula of magnetite ore.