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: Microbiology
[{'content': 'False about complement is \nSelect and explain. \nA. Group of proteins normally found is serum, B. Constitute about 20% of normal serum proteins, C. Heat labile, D. Species non-specific', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Constitute about 5% of normal serum proteins.', 'role': 'assistant'}]