The bone matrix has the following crystals -

Ans. is 'a' i.e., Calcium hydroxyapatiteStructure of boneo Bone is a specialized connective tissue.o Bone components areInorganic elements (65%)Organic matrix (35%)1. Inorganic elementsIt is the mineral phase, principally composed of calcium and phosphate, mostly in the form of hydroxyapatite ,2. Organic maxtixOrganic matrix consists of cells of bones and protein of matrix. This unminerilized matrix is called osteoid, i.e. unminerilized bone is known as oteoid. Osteoid with mineral (i.e. mineralized osteoid) is complete bone.Protein of matrixo It is mainly formed by type I collagen and a family of noncollagenous proteins like osteocalcin and osteonectin that are derived mainly from osteoblasts.Cells of matrixo The cells of bone areOsteoblastsOsteoclastsOsteocytes