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': 'A patient on total parenteral nutrition for 20 days presents with weakness, vertigo and convulsions. Diagnosis is: \nSelect and explain. \nA. Hypomagnesemia, B. Hyperammonemia, C. Hypercalcemia, D. Hyperkalemia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]