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': 'Hirschberg test is used to detect: \nSelect and explain. \nA. Squint, B. Field defects, C. Glaucoma, D. Optic atrophy', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Squint', 'role': 'assistant'}]