In a child of 15 years age, plasma calcium level is diagnosed below optimum level, which organ is malfunctioning?

The condition of having low calcium levels in the blood serum is referred to as Hypocalcemia. Though mildly low levels which develop slowly may not show any symptoms. The common causes of this include hypoparathyroidism and vitamin D deficiency. Hypoparathyroidism is the decreased function of parathyroid glands and underproduction of parathyroid hormone. it is the role of the parathormone to maintain the blood calcium levels. If a person is found to have low levels of calcium then it indicated abnormal parathormone production which could be due to malfunctioning of parathyroid hormone. Thus, the correct answer is C.