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
IL_2 is secreted by - 
Select and explain. 
A. CD4 lymphocytes, B. CD8 cells, C. Macrophages, D. Neutrophils
A: CD4 lymphocytes
Answer: A: CD4 lymphocytes 
Explanation: IL-2 produced by activated T cells, which induced T cell proliferation and enabled their maintenance in continuous culture REF:Ananthanarayan & Panikers Textbook of Microbiology 9th Edition pg:155