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: Biochemistry
[{'content': "Perl's stain or prussion blue test is for: \nSelect and explain. \nA. Bilirubin, B. Calcium, C. Hemosiderin, D. Glycogen", 'role': 'user'}, {'content': "Answer: C \nExplanation: Perls' stain (Prussian-Blue Reaction) is to demonstrate Ferric salts in tissues. These are seen as iron\xa0 granules in bone marrow macrophages, erythroblasts (Sideroblasts) and erythrocytes (Siderocytes) in\xa0 blood ﬁlms and haemosiderin in spun urine.", 'role': 'assistant'}]