This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
[{'content': 'Antigen binding site in immunoglobulin is - \nSelect and explain. \nA. Variable region, B. Hypervariable region, C. Constant region, D. Idiotype', 'role': 'user'}, {'content': "Answer: B \nExplanation: The antigen combining site of the immunoglobulin molecule is at its amino terminus. - it is composed of both L and H chains. - the first 110 amino acid from the N terminal are quite variable in amino acid sequence and this region is called variable region. Reference : Anathanarayan & paniker's 9th edition, pg no: 94 <\\p>", 'role': 'assistant'}]