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': 'In heterophoria prism is used: \nSelect and explain. \nA. With apex towards the direction of phoria in glasses for treatment, B. With apex towards the direction of phoria for exercises only, C. For exercises mainly in hyperphoria, D. To detect grade III of binocular vision', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. With apex towards the direction of phoria in glasses for treatment', 'role': 'assistant'}]