This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2018, Subject name: Gynaecology & Obstetrics
True about endometriosis: 
Select and explain. 
A. Presence of endometrial gland in deep myometrium, B. Presence of endometrium at ectopic locations, C. Treated preferably with hysterectomy, D. Seen in multiparous women
B: Presence of endometrium at ectopic locations
Answer: B: Presence of endometrium at ectopic locations 
Explanation: Endometriosis Presence of endometrial tissue at ectopic location Etiology : Retrograde menstruation Proposed by Sampsons ( Sampsons Implantation theory) 70-80% of all women have retrograde menses Among them 5-10% have poor immunity and | estrogenecity and develops Endometriosis NOTE: Option A, C, D, are related to Adenomyosis