This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'U shaped dose response curve is seen in \nSelect and explain. \nA. Vitamins, B. Anti cancer drugs, C. Steroids, D. Chelators', 'role': 'user'}, {'content': 'Answer: A \nExplanation: U shaped response curve is seen in vitamins Ref-Goodman and Gillman 12/e p74', 'role': 'assistant'}]