Assertion and reason type

Crystalline solids are callled anisotropic i.e., some of their physical properties like electricalresistance or refraction index show different values when measured in different directions in the same crystal.

Crystalline solids are anisotropic because there physical properties have different values in different direction.also it's the property of crystalline solids that atoms are closely packed that's why assertion and reason both are correct but not the correct explanation of each other