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': 'Most frequent site of metastasis in a case of Choriocarcinoma is: \nSelect and explain. \nA. Vagina, B. Liver, C. Lungs, D. Brain', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Lungs', 'role': 'assistant'}]