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': 'Tritanopes have defective assessment of whichcolor ? \nSelect and explain. \nA. Red, B. Blue, C. Green, D. Yellow', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is `b' i.e., Blue Colour Defective Absent GreenRedBlue DeuteranomalousProtanomalousTritsnomalous DeuteranoPtaProtanopiaTritanopia", 'role': 'assistant'}]