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: Forensic Medicine
[{'content': "Retraction balls' after trauma are seen in: PGI 08, 11; UP 12 \nSelect and explain. \nA. Brain, B. Spleen, C. Liver, D. Lung", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Brain', 'role': 'assistant'}]