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
Ligneous conjunctivitis is caused by: 
Select and explain. 
A. Purulent conjunctivitis, B. Membranous conjunctivitis, C. Angular conjunctivitis, D. Phlyctenular conjunctivitis
B: Membranous conjunctivitis
Answer: B: Membranous conjunctivitis 
Explanation: Ans. Membranous conjunctivitis