Identifying the pituitary gland as source of luteinising hormone

Steps:

• Recall that endocrine glands produce specific hormones; identify X by matching hormone origins.
• Luteinising hormone (LH) is secreted by the anterior pituitary gland.
• Eliminate options based on mismatched gland locations: adrenaline from adrenal medulla, glucagon from pancreas, progesterone from ovaries.
• Confirm X matches the pituitary based on LH production.

Why C is correct:

• Luteinising hormone is defined as a gonadotropin produced by the anterior pituitary gland to regulate reproductive functions.

Why the others are wrong:

• A: Adrenaline is produced by the adrenal medulla, not X.
• B: Glucagon is secreted by pancreatic alpha cells.
• D: Progesterone originates from the ovaries or placenta.

Final answer: C