Before the discovery of these glands, thyroid surgery often led to a rapid drop in blood calcium levels,which triggered muscle contractions and cardiac arrhythmias. What glands are these and which hormone is lacking?
A) thyroid glands; calcitonin B) parathyroid glands; calcitonin C) parathyroid glands; parathyroid hormone D) thyroid glands; levothyroxine E) parathyroid glands; levothyroxine