This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General obstetrics, Subject name: Gynaecology & Obstetrics
[{'content': 'Choriocarcinoma commonly metastasize to: \nSelect and explain. \nA. Brain, B. Lung, C. Vagina, D. Ovary', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Symptoms peaining to metastasis elsewhere like haemoptysis or features suggestive of an intracranial space occupying lesion.It can also present as vaginal metastasis.The common sites of metastasis are the lungs in 75% and suburethral vaginal metastasis in 50%.Theca lutein cysts of the ovaries are usually seen (refer pgno:173 sheila textbook of obstetrics 2 nd edition)', 'role': 'assistant'}]