This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diseases of orbit, Lids and lacrimal apparatus, Subject name: Ophthalmology
Mucin layer tear film deficiency occurs in - 
Select and explain. 
A. Keratoconjunctivitis sicca, B. Lacrimal gland removal, C. Canalicular block, D. Herpetic keratitis
A: Keratoconjunctivitis sicca
Answer: A: Keratoconjunctivitis sicca 
Explanation: Also known as sjogrens syndrome or aqueous deficiency dry eye. Ref : ak khurana 6th edition