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: Ophthalmology
[{'content': "Test for colour vision \nSelect and explain. \nA. Ishihara plates, B. Holmgren's wool test, C. City university test, D. All the above", 'role': 'user'}, {'content': "Answer: D \nExplanation: Others\nEdridge - Green lantern test.\nFans worth D 15 hue discrimination\xa0test.\nNagel's anomaloscope.\nHardy - Rand - Rittler plates.", 'role': 'assistant'}]