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': 'Plasma cells produce specific antibodies by the process of? \nSelect and explain. \nA. Class selection, B. Clonal selection, C. Isotope selection, D. Isotope switching', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Clonal selection\n\nB-cells are able to make a specific antibody against a specific antigen. It is due to the presence of specific\xa0receptor on B-cells - B-cell receptor (BCR), that is usually an immunoglobulin Ig M or Ig D. An antigen\xa0interacts with B-cell that shows best fit by virtue of its BCR. The antigen binds to this receptor, and the\xa0B-cell is stimulated to divide and form a clone (clonal selection). This clone of cells will become plasma\xa0cells that will secrete antibody of a particular specificity and same class.\nPlasma cells make an antibody of a single specificity, of a single immunoglobulin class and allotype, and\xa0of a single light chain type only. An exception is seen in the primary antibody response, when a plasma\xa0cell producing IgM initially, may later be switched to IgG production (called isotype switching or class\xa0switching).', 'role': 'assistant'}]