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': 'Which one of the following immunoglobulins constitutes the antigen binding component of B-cell receptor -a) IgAb) IgDc) IgMd) lgG \nSelect and explain. \nA. a, B. bc, C. ac, D. ad', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B cells display immunoglobulin molecules on their surface. These immunoglobulins serve as receptors for a specific antigen, so that each B cell can respond to only one antigen or a closely related group of antigens. All immature B cells carry Ig M immunoglobulins on their surface and most also early Ig D.\nCombination of cell membrane bound Ig M or Ig D with the corresponding antigen leads to specific stimulation of the B cells - either activation and cloning to produce antibody, or suppression.\n\n\nB cells also have surface receptors for the Fe portion of inununogloblins and for several complement components.', 'role': 'assistant'}]