Wolff's Law primarily addresses what concept in bone dynamics?

Wolff's Law is a foundational principle in understanding bone dynamics, stating that bone adapts to the loads under which it is placed. When mechanical stress is applied to a bone, it responds by changing its structure to strengthen and grow in areas that are subjected to greater stress, while areas that are not stressed may become weaker and potentially shrink. This adaptive response reflects the principle that bone is a living tissue capable of remodeling based on the demands placed upon it.

In this context, the choice that indicates how bones can grow or shrink directly relates to Wolff's Law, as it captures the dynamic nature of bone structure in response to mechanical load. Conversely, the other options do not encapsulate this fundamental idea; for instance, discussing brittleness pertains to bone density and material weaknesses rather than the response to mechanical loading, and the uniformity of density or healing processes are secondary implications rather than the core tenet of how bones adapt based on loading activities.