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: Social & Preventive Medicine
[{'content': 'All are true about Yaws except \nSelect and explain. \nA. Caused by Treponema pertenue, B. Transmitted non-venerally, C. Later stages involve heart and nerves, D. Secondary Yaws can involve bones', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]