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
All are known to cause conjunctival xerosis except: 
Select and explain. 
A. Trachoma, B. Membranous conjunctivitis, C. Angular conjunctivitis, D. Ocular pemphigoid
C: Angular conjunctivitis
Answer: C: Angular conjunctivitis 
Explanation: Ans. Angular conjunctivitis