Which classification of magnetic materials includes materials that can be magnetized but not easily?

The classification of magnetic materials that includes those which can be magnetized but not easily is paramagnetic materials. Paramagnetic materials have unpaired electrons, which allow them to respond weakly to an external magnetic field. When subjected to a magnetic field, these materials can become magnetized, but this magnetization is generally weak and temporary, dissipating once the external field is removed.

This is in contrast to ferromagnetic materials, which have a strong ability to be magnetized and retain their magnetization even after the external magnetic field is gone. Diamagnetic materials, on the other hand, have no unpaired electrons and are characterized by a very weak negative response to a magnetic field, effectively repelling it rather than being magnetized. The choice of conductive, while relevant in the context of electrical conductivity, does not pertain to magnetic properties or classification regarding magnetization.

Therefore, paramagnetic materials are accurately described as those that can be magnetized to some extent, albeit not easily, which is why this classification is the correct answer.