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': 'Systemic metastasis is commonest in : \nSelect and explain. \nA. Ovarian Carcinoma, B. Endometrial Carcinoma, C. Choriocarcinoma, D. Carcinoma cervix', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Choriocarcinoma', 'role': 'assistant'}]