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': 'The most common systemic association of scleritis is – \nSelect and explain. \nA. Ehlers – Danlos syndrome, B. Disseminated systemic sclerosis, C. Rheumatiod arthritis, D. Giant cell arteritis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: "When a patient comes to an ophthalmologist with scleritis, RA must be considered, because it is the most common cause of scleritis (and episcleritis)".\n— The cornea by Dohlman', 'role': 'assistant'}]