This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
[{'content': 'The ocular basement membrane is stained with \nSelect and explain. \nA. Alcaine blue, B. Giemsa stain, C. Methylene blue, D. Periodic acid-Schiff', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Not only ocular almost all basement membranes are stained with PAS (Periodic acid-Schiff) Because they have mucopolysaccharides.Periodic acid-Schiff reactive (PAS) method is principally used to demonstrate structures rich in polysaccharides (glycogen), mucopolysaccharides (e.g., ground substance of connective tissues, basement membrane, and mucus), glycoproteins (thyroglobulin), and glycolipids.', 'role': 'assistant'}]