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': '”HOT SPOT” is the region of antibody which is also called \nSelect and explain. \nA. hinge portion, B. hypervariable region, C. constant region, D. disulphide bond rich region', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]