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 hyperplasia is caused by : 
Select and explain. 
A. Oestrogen, B. Smoking, C. Ovulation inducing drugs, D. Asherman's syndrome
A: Oestrogen
Answer: A: Oestrogen 
Explanation: Oestrogen