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
Which is true of endometriosis : 
Select and explain. 
A. Always associated with tubal blood, B. Painful, C. Amenorrhoea, D. Surgery Is curative
B: Painful
Answer: B: Painful 
Explanation: Painful