Question

what hormone is made by the parafollicular cells of the thyroid gland?
parathyroid hormone (pth)
calcitonin
thyroxine (t4)
triiodothyronine (t3)

Explanation:

Parafollicular cells (C - cells) of the thyroid gland secrete calcitonin. Parathyroid hormone (PTH) is made by the parathyroid glands. Thyroxine (T4) and triiodothyronine (T3) are produced by the follicular cells of the thyroid gland.

Answer:

Calcitonin