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: Radiology
[{'content': 'Local cerebral lesion with a ring on CT scan is caused by – \nSelect and explain. \nA. Toxoplasmosis, B. Intracranial haemorrhage, C. Cysts, D. Hamartoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Toxoplasmosis can cause ring-enhancing brain lesions.', 'role': 'assistant'}]