This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Twin Pregnancy, Molar Pregnancy, Gestational Trophoblastic disease and contraception in special situations (Sour Grapes!), Subject name: Gynaecology & Obstetrics
[{'content': 'A case of Gestational trophoblastic neoplasia is detected to have lung metastasis. She should be staged as \nSelect and explain. \nA. Stage - I, B. Stage - II, C. Stage - III, D. Stage - IV', 'role': 'user'}, {'content': 'Answer: C \nExplanation: FIGO staging system of GTN: Stage I: Disease confined to the uterus Stage II: Gestational trophoblastic tumor (GTT) extends outside of the uterus but is limited to the genital structures (ovary, tube, vagina, and broad ligament) Stage III: GTT extends to the lungs, with or without known genital tract involvement Stage IV: All other metastatic sites', 'role': 'assistant'}]