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: Pathology
Occular basement membrane is stained by ? 
Select and explain. 
A. Alcian blue, B. PAS, C. Methylene blue, D. Geimsa stain
B: PAS
Answer: B: PAS 
Explanation: Ans. is 'b' i.e., PASBasement membranes are periodic acid-Schiff (PAS) positive amorphous structures that lie underneath epithelia of differenent organs.