e brain is known as the master gland controller? Thalamus is incorrect because it refers to a different organ, substance, process, or medical association. Cerebrum is also incorrect; it may be biologically important, but its principal role or defining feature is not the one being tested here. Pons is incorrect because its function, source, target, or disease relationship does not match the question. Therefore option B, Hypothalamus, is factually consistent with the stem, the marked correct index, and the explanation. Hypothalamus controls the pituitary gland (master gland) and regulates body temperature hunger thirst and circadian rhythms.