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 ring on CT scan is caused by: \nSelect and explain. \nA. Toxoplasmosis, B. Intracranial haemorrhage, C. Cysts, D. Hamaoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Toxoplasmosis Conditions causing ring-enhancement with CT (contrast) - ToxoplasmosisQ - Cysticercosis - TuberculomaQ - Pyogenic abscess - Glioma metastasis - Craniopharyngeoma - Gaint aneurysm', 'role': 'assistant'}]