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: Pathology
The cause of scleritis is - 
Select and explain. 
A. Collagen vascular disease, B. TB, C. Trauma, D. Glaucoma
A: Collagen vascular disease
Answer: A: Collagen vascular disease 
Explanation: Scleritis is commonly associated with connective tissue disease (including collegen vascular disease) such as → RA, SLE, PAN, Wegener's granulomatosis, Relapsing polychondritis.