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': 'In a patient diagnosed to have choriocarcinoma which is the most common site of metastasis? \nSelect and explain. \nA. Liver, B. Lungs, C. Brain, D. Ovaries', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Lungs are the most common site of metastasis (75%) followed by vagina (50%). The vulva, kidneys, liver, ovaries, brain, and bowel also may contain metastases. Metastases often develop early and are generally blood-borne because of the affinity of trophoblastic cells for blood vessels.', 'role': 'assistant'}]