Parathyroid hormone does not regulate magnesium.
So, the option (a) is incorrect.
Para thyroid hormone does not regulate calcitonin, which is a 32 amino acids linear polypeptide hormone that is produced in humans by the Para follicular cells of the thyroid.
Therefore, the option (c) is incorrect.
Para thyroid hormone does not even regulate glucocorticoid, which is a class of corticoids, which are steroid Harmons present in every vertebrate animal.
Hence the option (d) is also incorrect.
As the para thyroid hormone deals with calcium.
So, the correct answer is