<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:An immunology expert is explaining the functions of macrophages to biology students. He describes a hypothetical case scenario as follows: a potentially harmful gram-negative bacillus encounters a macrophage in the tissues. The Toll-like receptor TLR on the macrophage recognizes the bacterial lipopolysaccharide LPS. The macrophage is activated by the binding of TLR with bacterial LPS and by interferon-γ IFN-γ. Which of the following cytokines is most likely to be secreted by the activated macrophage?? A: Interleukin-1 receptor antagonist IL-1RA, B: Interleukin-2 IL-2, C: Interleukin-4 IL-4, D: Interleukin-10 IL-10, E: Interleukin-12 IL-12,  <response>: This question describes a scenario where a macrophage encounters and recognizes a gram-negative bacterium via the TLR and IFN-γ pathway, leading to macrophage activation. It then asks which cytokine would most likely be secreted by the activated macrophage. Choices A, B, and C are anti-inflammatory or Th2-type cytokines that would downregulate inflammation. Choice D, IL-10, is also an anti-inflammatory cytokine. Choice E, IL-12, is a pro-inflammatory Th1-type cytokine that would promote cell-mediated immunity against an intracellular bacterial pathogen. Macrophages classically activated by IFN-γ and TLR signaling typically secrete IL-12.Therefore, IL-12 is the most likely cytokine to be secreted by the activated macrophage in this scenario.E: Interleukin-12 IL-12 