Explanation

 Ferromagnetic materials are those that can retain a permanent magnetization even after an external magnetic field is removed.

This property is due to the aligned magnetic domains within the material.

Iron (Fe), Cobalt (Co), and Nickel (Ni) are all ferromagnetic.

Antimony (Sb), on the other hand, is not ferromagnetic; it is classified as diamagnetic, meaning it repels a magnetic field.