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
[{'content': 'A young woman with six weeks amenorrhea presents with mass abdomen. USG shows empty uterus. Diagnosis is: \nSelect and explain. \nA. Ovarian cyst, B. Ectopic pregnancy, C. Complete aboion, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Young woman with six weeks of amenorrhea and mass in the abdomen and USG finding of empty uterus give the diagnosis of ectopic pregnancy. Ref: Textbook of Obstetrics By D.C.Dutta, 5th Edition, Page 198 ; Ultrasound in Obstetrics and Gynecology, Volume 1 By Eberhard Merz, F. Bahlmann, 2004, Page 73 ; Management of Common Problems in Obstetrics and Gynecology Edited By T. Murphy Goodwin, Main N. Montoro, Laila Muderspach, Richard Paulson, Subir Roy, 2010, Page 275', 'role': 'assistant'}]