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: Pharmacology
[{'content': 'All are features of ethambutol toxicity, except ? \nSelect and explain. \nA. Retrobulbar neuritis, B. Colour vision defects, C. Hyperuricemia, D. Hypercalcemia', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Hypercalcemia", 'role': 'assistant'}]