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
Epithelial xerosis of the conjunctiva is caused by 
Select and explain. 
A. Trachoma, B. Xerophthalmia, C. Diphtheria, D. Pemphigus
B: Xerophthalmia
Answer: B: Xerophthalmia 
Explanation: Epithelial xerosis:  It occurs due to hypovitaminosis -A. 
Epithelial xerosis may be seen in association with night blindness or as a part and parcel of the xerophthalmia (the term which is applied to all ocular manifestations of vitamin A deficiency which ranges from night blindness to keratomalacia