Answer: Option C
Explanation:
Calcitonin plays a minor role in controlling the levels of calcium in the bloodstream. It inhibits the activity of osteoclasts, which comprises of the cell that is responsible for the breaking down of bone.
When the bone is broken down its concentration in the blood stream increases. It stimulates the kidney to absorb the calcium when it is too low.
While the parathyroid hormone stimulates the kidney to excrete calcium when calcium levels are high,.