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: Pathology
[{'content': 'Serous papillary cystadenocarcinomas of the ovaries express \nSelect and explain. \nA. CA-125, B. CA-19, C. CEA, D. AFP', 'role': 'user'}, {'content': 'Answer: A \nExplanation: CA-125', 'role': 'assistant'}]