This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nasolacrimal Disorders, Subject name: Ophthalmology
Which of the following stain is used to assess tear film integrity:- 
Select and explain. 
A. Congo red, B. Alcian Blue, C. Rose bengal, D. All of the above
C: Rose bengal
Answer: C: Rose bengal 
Explanation: Tests for Tear Film and Epithelial Integrity Stains used commonly : -Fluorescein -Rose Bengal -Lissamine green -Rhodhamine Blue Fluorescein Stains exposed basement membrane Stains cornea more than conjunctiva. For diagnosing Filamentary keratitis, measuring TBUT CORNEAL STAINING OF DRY EYE USING FLUORESCEIN STAINING CONJUNCTIVAL STAINING IN DRY EYE USING FLUORESCEIN STAINING. CONJUNCTIVAL VASCULAR TOUOUSITY IS ALSO EVIDENT Rose Bengal Stains dead and devitalised cells Healthy cells protected inadequately by a mucin coating Irritation on instillation Early or mild cases detected more easily with Rose Bengal Stain more visible on conjunctiva than cornea Interpalpebral staining of the nasal and/or inferior paracentral cornea is seen in KCS