The hypothalamus regulates the . a. thalamus
b. pineal gland
c. pituitary gland
d. pons

c. pituitary gland

Explanation:

The hypo(below) thalamus is an almond size structure located superiorly to the brainstem. it is located below the thalamus. Hence the name hypothalamus.

It is primary function is is to control the body homeostatic functions of sleeping and waking up, sex, thirst and hunger etc.

It performs these roles by serving as the primary link of the nervous system with the endocrine system. Pituitary gland is an example of  endocrine gland that secrets many hormones. (they are called endocrine because the hormones are secreted directly into the blood streams.

Its activities are controlled by the nervous stimulation from hypothalamus. Therefore the instructions to secretes certain hormones to the post and anterior part of the pituitary gland depends on the hypothalamus.

Growth hormones, oestrogen, and thyroid are examples of hormones of the pituitary glands.