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': "Best Investigation to assess tubal patency: \nSelect and explain. \nA. Rubin's test, B. HSG, C. Laparotomy, D. Laparoscopic chromtubation", 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]