This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition and health, Subject name: Social & Preventive Medicine
Rose-Bengal test is - 
Select and explain. 
A. To detect the presence of conjunctival xerosis, B. To test the pasteurized milk, C. To detect the rabies antigen in corneal cells, D. Is positive in connective tissue disorder
A: To detect the presence of conjunctival xerosis
Answer: A: To detect the presence of conjunctival xerosis 
Explanation: <p> Rose bengal test: It is a very useful test for detecting even mild cases of KCS (keratoconjuctivitis sicca). Depending upon the severity three staining patterns A,B and C have been described. A- severe cases with confluent staining of conjunctiva and cornea. B- moderate cases with extensive staining. C- mild/early cases with fine punctate stains in the interpalpebral area. {Reference: ophthalmology , A.K khurana}