The correct answer is B. A ferromagnetic material has the highest permeability.
Diamagnetic materials are slightly repelled by a magnetic field. Paramagnetic materials are slightly attracted to a magnetic field. Ferromagnetic materials are strongly attracted to a magnetic field.
The permeability of a material is a measure of how easily a magnetic field can be established in the material. The permeability of a ferromagnetic material is much higher than the permeability of a diamagnetic or paramagnetic material.
For example, the permeability of iron is about 100,000 times the permeability of air. This means that a magnetic field can be established in iron 100,000 times more easily than it can be established in air.
Ferromagnetic materials are used in many applications where a strong magnetic field is needed, such as in motors, generators, and transformers.