Question

when stress is applied to a bone, the minerals in the bone produce a weak electrical field that attracts osteoblasts. the bone becomes thin and brittle and ultimately fractures. osteoclast activity increases and osteoblast activity decreases. the bone compensates by becoming thinner in the region of stress. blood supply through the nutrient artery diminishes and thus remodeling proceeds at a much slower rate.

Explanation:

When stress is applied to a bone, piezoelectric effect occurs in bone minerals. This generates a weak electrical field which attracts osteoblasts that help in bone - building. The other options are incorrect as normal stress doesn't immediately cause bone to become thin and brittle or fracture, nor does it decrease osteoblast activity or blood supply. Also, bone doesn't become thinner in the stress - region but rather adapts by thickening in healthy circumstances.

Answer:

the minerals in the bone produce a weak electrical field that attracts osteoblasts.