The correct option is
A Hypoparathyroidism
The muscle cramping associated with tetany can be long lasting and painful. A common cause of tetany is very low levels of calcium in the body. The medical term for low calcium is hypocalcemia. Tetany is a disorder characterized by enhanced neuromuscular excitability that is caused by various metabolic abnormalities. Hypoparathyroidism results in diminished concentration of parathyroid hormone in the blood, which causes deficiencies of calcium and phosphorus compounds in the blood and results in muscular spasms.
So, the correct answer is 'Hypoparathyroidism'