Answer:
(b). gonads
Step-by-step explanation:
Pituitary gland can be defined as an endocrine gland, which regulates functions of various glands by synthesizing and secreting various hormones. Gonads are under regulation of hypothalamic-pituitary pathway.
The anterior pituitary gland secreted LH (luteinizing hormone) and FSH (follicle-stimulating hormone), which stimulate gonads to release testosterone and estrogen.
On the other hand, parathyroid gland, pancreas, and medulla work independently and do not depend on hormones released from pituitary.
Hence, dysfunction of pituitary gland would mainly affect the functioning of gonads.
Thus, the correct answer is option (b).