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': 'Commonest ovarian tumor complicating pregnancy is : commonest ovariantumor complicating preg? nancy is : \nSelect and explain. \nA. Fibroma, B. Mucinous cystadenocarcinoma, C. Serous cystadenocarcinoma, D. Dermoid', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Dermoid', 'role': 'assistant'}]