Concept:The inorganic matrix of bone is composed mainly of calcium and phosphorus, with magnesium as a minor component.
Explanation:Bone hardness comes from inorganic salts, chiefly calcium phosphate,
Ca3(PO4)2.
Small amounts of magnesium are also present in the bone matrix.
Sodium and potassium occur only in trace amounts and are not the primary inorganic components.
Hence, the correct combination is magnesium, phosphorus, and calcium.
Answer:B. magnesium, phosphorus and calcium