What is magnetic anisotropy? How are the setbacks of anisotropy dealt with in magnetostrictive nanocomposites?

a) Magnetic anisotropy refers to the directional dependence of a material's magnetic properties. Setbacks are dealt with by using isotropic materials in magnetostrictive nanocomposites.
b) Magnetic anisotropy refers to the uniformity of a material's magnetic properties. Setbacks are dealt with by applying external magnetic fields in magnetostrictive nanocomposites.
c) Magnetic anisotropy refers to the lack of directional dependence of a material's magnetic properties. Setbacks are dealt with by using anisotropic materials in magnetostrictive nanocomposites.
d) Magnetic anisotropy refers to the non-uniformity of a material's magnetic properties. Setbacks are dealt with by using isotropic materials in magnetostrictive nanocomposites.