This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
Endometrial implants are deficient in which enzyme 
Select and explain. 
A. Aromatase, B. 17 β - hydroxysteroid dehydrogenase type 2, C. 17 β - hydroxysteroid dehydrogenose type 1, D. 17 α - hydroxylase
B: 17 β - hydroxysteroid dehydrogenase type 2
Answer: B: 17 β - hydroxysteroid dehydrogenase type 2 
Explanation: 17 β - hydroxysteroid dehydrogenase type 2,which inactivates estrogen is absent in endometrial implants.