This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Conjunctiva, Subject name: Ophthalmology
[{'content': 'Visual impairments in pterygium is due to - \nSelect and explain. \nA. Astigmatism, B. Myopia, C. Hypermetropia, D. Hazy cornea', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Visual disturbances occur when pterygium encroches the pupillary area or due to corneal astigmatism induced due to fibrosis in the regressive stage. Reference : Khurana 7th edition, page : 89', 'role': 'assistant'}]