This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrine System, Subject name: Physiology
[{'content': 'Pregnenolone is not in the biosynthetic pathway of which substance? \nSelect and explain. \nA. Coisol, B. Estrogen, C. DHEA, D. 1,25(OH)2D', 'role': 'user'}, {'content': 'Answer: D \nExplanation: All the steroids listed include pregnenolone early in their biosynthetic pathway. 1,25(OH)2D is derived from vitamin D and does not include pregnenolone in its biosynthetic pathway.', 'role': 'assistant'}]