Read the following statements about the parathyroid gland. Identify the true and false statements among them and select the correct option. I. Human beings have a pair of parathyroid glands, situated in each lobe of the thyroid gland. II. The secretion of PTH is regulated by the levels of circulating calcium ions. III. PTH is a hypocalcemic hormone. IV. PTH plays a major role in maintaining calcium balance in the body along with TCT.