Hardened steel is difficult to magnetize; what does it relate to when being demagnetized?

When considering the relationship between hardened steel's difficulty in being magnetized and its properties related to demagnetization, low permeability is the key factor. Permeability refers to a material's ability to support the formation of a magnetic field within itself. In general, materials with low permeability do not allow magnetic lines of force to pass through them easily.

This characteristic means that once hardened steel is magnetized, it will also resist demagnetization, because it does not readily allow magnetic forces to flow through its structure. Therefore, when discussing demagnetization, low permeability indicates that the material does not easily lose its magnetism as it requires a stronger opposing magnetic field to neutralize its magnetization.

Materials with high permeability would easily become magnetized and demagnetized, while those with no permeability would not allow any magnetic effects at all. Average permeability represents a middle ground that does not accurately capture the essential difficulty of demagnetizing hardened steel, making low permeability the most appropriate answer in this context.