The fact that the shards of the magic mirror are scattered throughout the world suggests the idea that:
C) Evil is a subtle and pervasive force that can corrupt even the purest of hearts.
This interpretation aligns with the notion that evil can be widespread and can influence individuals in various ways, even when they least expect it. The scattering of the shards implies that evil is not confined to one area or entity, but rather exists in different forms and locations, capable of touching anyone.