This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunity, Subject name: Pathology
[{'content': 'Circulating antibodies formed by? \nSelect and explain. \nA. T-cells, B. B-cells, C. Macrophages, D. Plasma cells', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Plasma cells * Plasma cells are the antibody secreting cells. On contact with its appropriate antigen, the mature B cell undergoes clonal proliferation. The majority of activated B cells are transformed into plasma cells and secrete antibodies* While plasma cell is the best antibody producing cell, lymphocytes, lymphoblasts and transitional cells may also synthesise Ig to some extent", 'role': 'assistant'}]