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': 'For myositis ossificans, main cause is? \nSelect and explain. \nA. Infection, B. Hereditary, C. Benign pathology, D. Trauma', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Myositis ossificans progressive is a disease of unknown etiology characterised by formation of fibrous tissue and bone within interstitial tissues of muscles, tendons, fascia, ligaments, aponeurosis and even the skin. Most cases of myositis ossificans occur as a result of trauma, and thus the main demographic is young adults.', 'role': 'assistant'}]