This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Physiology
[{'content': 'All are required for formation of estradiol except \nSelect and explain. \nA. Lyase, B. 11b-hydrolase, C. Aromatase, D. Hydroxysteroid dehydrogenase', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 11b hydroxylase is not required for estradiol synthesis. Ref: Guyton and Hall 13th edition Pgno: 967', 'role': 'assistant'}]