Final answer:
The hypothalamic hormone that regulates thyroid hormone is Thyrotropin Releasing Hormone (TRH).
Step-by-step explanation:
The hypothalamic hormone that regulates thyroid hormone is Thyrotropin Releasing Hormone (TRH). TRH is produced by the hypothalamus and stimulates the secretion of Thyroid-Stimulating Hormone (TSH) from the anterior pituitary gland. TSH, in turn, controls the release of the thyroid hormones thyroxine (T4) and triiodothyronine (T3) from the thyroid gland. The correct answer is therefore c. TRH