This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous System, Subject name: Physiology
Posterior pituitary hormone secretion is mediated by: 
Select and explain. 
A. A portal capillary system from the hypothalamus to the posterior pituitary, B. The fight-or-flight response, C. The hypothalamo-hypophyseal tract originating from magnocellular neurons in the supraoptic and paraventricular nuclei, D. The reticular activating system's input to the hypothalamus
C: The hypothalamo-hypophyseal tract originating from magnocellular neurons in the supraoptic and paraventricular nuclei
Answer: C: The hypothalamo-hypophyseal tract originating from magnocellular neurons in the supraoptic and paraventricular nuclei 
Explanation: Ans. C. The hypothalamo-hypophyseal tract originating from magnocellular neurons in the supraoptic and paraventricular nucleiMagnocellular neurons of the paraventricular and supraoptic nuclei of the hypothalamus, whose axons reach the posterior pituitary via the hypothalamo-hypophyseal tract, secrete the posterior pituitary hormones. The portal capillary system from the hypothalamus to the pituitary gland is associated with the anterior pituitary. While pituitary function may be altered by the fight-or-flight response, the reticular activating system, or emotional state, none of these directly mediates posterior pituitary hormone secretion.