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
Risk for endometrial cancer is:a) Obesityb) Pregnancy before 20 years agec) PCODd) Combined OC pillse) Artificial menopause 
Select and explain. 
A. a, B. ac, C. ad, D. b
B: ac
Answer: B: ac 
Explanation: None