This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Conjunctiva, Subject name: Ophthalmology
[{'content': 'A 10 year old malnourished boy presents with a nodular elevation on the Limbus which is congested, and stains positive with fluorescein. Tentative diagnosis? \nSelect and explain. \nA. Pterygium, B. Pinguecula, C. Phlycten, D. Nodular episcleritis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Phlycten- phlyctenular keratoconjunctivitis is an allergic response of conjunctiva and cornea . Tuberculous proteins were considered, previously, as the most common cause. Staphylococcus proteins are now thought to account for most of the cases. It is characterized by the presence of a typical pinkish white nodule surrounded by hyperaemia on the bulbar conjunctiva, usually near the limbus A pterygium frequently follows a pinguecula is often bilateral, present on the nasal side. Vision becomes impaired due to induced astigmatism or progression into the pupillary area of the cornea. Nodular episcleritis m/c in females presents with a red eye Attacks usually clear without treatment', 'role': 'assistant'}]