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
[{'content': 'Macrophage chemotactic factor is - \nSelect and explain. \nA. High molecular weight, B. Chymotrypsin sensitive, C. Heat labile, D. Are antigenically similar to C3', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans is 'b' i.e.,Chymotrypsin sensitive (Ref Immunology p. 278)Macrophage chemotactic factor propeies has Low molecular weight (12000), has a isoelectric points of 10.1 & 5.6, and is sensitive to treatment by chymotrypsin while resistant to RNase and neuraminidase.It is heat stable and angenically different from C3 & C5.", 'role': 'assistant'}]