is not secreted from an organ located in the abdominal cavity.

Correct Answer: D

Rationale: Calcitonin is from the thyroid (neck), not abdominal cavity.

Correct Answer: A

Rationale: Thyroxine-binding globulin (TBG) has the highest affinity for T_4, binding most of it in plasma.

Correct Answer: C

Rationale: Lysine is an essential amino acid that must be obtained from the diet, unlike glycine, serine, glutamine, and tyrosine, which can be synthesized.

Correct Answer: C

Rationale: MMC occurs during fasting to clear the gut, distinct from BER; secretions decrease, and Phase I is quiescent, not contractile.

Correct Answer: C

Rationale: Gastrin stimulates histamine release from ECL cells, increasing acid secretion; histamine acts via cAMP, not Ca2+.