This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gynaecological oncology, Subject name: Gynaecology & Obstetrics
[{'content': 'Ovarian tumour staging if one ovary involved without surface involvement or rupture \nSelect and explain. \nA. Stage 1A, B. Stage 1B, C. Stage 1C1, D. Stage 1C2', 'role': 'user'}, {'content': 'Answer: A \nExplanation: STAGE 1A: Ovarian cancer limited to one ovary without malignant ascites or positive peritoneal washings, surface involvement or rupture', 'role': 'assistant'}]