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': "A condition with collagenous degeneration of conjunctiva and invasion of corneal epithelium followed by destruction of stromal layer and Bowman's membrane: March 2011 March 2013 (a, c, f, g,) \nSelect and explain. \nA. Conjunctivitis, B. Trachoma, C. Pinguecula, D. Pterygium", 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. D: Pterygium A pterygium is a degenerative condition of the subconjunctival tissue which proliferate as vascularized granulation tissue to invade the cornea, destroying the superficial layers of the stroma and Bowman's membrane, the whole being covered by conjunctival epithelium", 'role': 'assistant'}]