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: Surgery
[{'content': 'Drug induced portal hypertension is seen with - \nSelect and explain. \nA. Vitamin A toxicity, B. Methotrexate, C. Aldomet, D. Valproic acid', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Normal doses of vitamin A are not associated with liver injury or liver test abnormalities, but higher doses can be toxic\nMechanism of Injury\n• Excess vitamin A is stored in stellate cells\xa0in the liver and accumulation can lead to their activation and hypertrophy, excess collagen production, fibrosis\xa0and liver injury.\n• Serum bilirubin is typically only mildly elevated.\n• Liver biopsy is diagnostic', 'role': 'assistant'}]