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': 'Cytokines are released by: September 2012 \nSelect and explain. \nA. Monocyte, B. Macrophage, C. T lymphocyte, D. B lymphocyte', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C i.e. T lymphocyte T helper cells (Th cells) They are a sub-group of lymphocytes that play an impoant role in the immune system, paicularly in the adaptive immune system. They help the activity of other immune cells by releasing T cell cytokines. They are essential in B cell antibody class switching, in the activation and growth of cytotoxic T cells, and in maximizing bactericidal activity of phagocytes such as macrophages.', 'role': 'assistant'}]