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': 'Nova T has the following : \nSelect and explain. \nA. Silver core, B. Copper core, C. Platinum core, D. Iron core', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Silver core', 'role': 'assistant'}]