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
Interleukin 2 is produced by 
Select and explain. 
A. T helper cells 2, B. Natural killer cells, C. T helper cells 1, D. Basophils
C: T helper cells 1
Answer: C: T helper cells 1 
Explanation: A) T helper -1 (TH1) secretes → IL-2 and interferon - γ
B) T helper - 2 (TH2) secretes → IL-4, IL-5, IL-6, IL-13