This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2019, Subject name: Physiology
Hormonal secretion are tightly controlled by the time of day due to an inbuilt biological clock in human body. This rhythmic secretion is controlled by: 
Select and explain. 
A. Supra optic nuclei, B. Postero lateral nucleus, C. Ventro-lateral nucleus, D. Supra-lateral nucleus
D: Supra-lateral nucleus
Answer: D: Supra-lateral nucleus 
Explanation: - Suprachiasmatic nucleus of hypothalamus is said to be the link between external environment and body's biological clock/ circadian rhythm, - We see day & night, this image falls on retina |One set of fibers are sent to suprachiasmatic nucleus | superior cervical ganglionFibers are sent to pineal gland. |Pineal gland accordingly secretes melatonin- Melatonin secretion levels determine hormonal secretions & their circadian rhythm.Eg: steroid levels - highest at early morning & low in evening.