Question

which of the following options best describes the structure of bone?
a a mixture of hardened collagen and minerals
b chondroitin sulfate secreted by chondrocytes
c many columnar epithelial cells packed together
d hardened fibrous connective tissue

Explanation:

Bone is a connective tissue. It consists of collagen fibers (a protein) that provide flexibility and strength, and minerals (such as calcium phosphate) that harden the tissue. Chondroitin sulfate is related to cartilage (not bone), columnar epithelial cells are part of epithelial tissue (not bone - forming), and while bone is a type of connective tissue, the more specific description is a mixture of collagen and minerals.

Answer:

A. a mixture of hardened collagen and minerals