This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endometriosis and dysmenorrhea, Subject name: Gynaecology & Obstetrics
[{'content': 'Best investigation endometriosis is : \nSelect and explain. \nA. Laparoscopy, B. USG, C. X-ray pelvis, D. CT Scan', 'role': 'user'}, {'content': "Answer: A \nExplanation: Laparoscopy is the gold standard in the diagnosis of endometriosis. The diagnosis should be validated by peritoneal and tissue biopsy, because corpus luteal haematoma can resemble a chocolate cyst. Reference: Shaw's Textbook of Gynaecology 16th edition page no 415", 'role': 'assistant'}]