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
All are required for formation of estradiol except 
Select and explain. 
A. Lyase, B. 11b-hydrolase, C. Aromatase, D. Hydroxysteroid dehydrogenase
B: 11b-hydrolase
Answer: B: 11b-hydrolase 
Explanation: 11b hydroxylase is not required for estradiol synthesis. Ref: Guyton and Hall 13th edition Pgno: 967