The following are multiple choice questions (with answers) about medical knowledge.   **Question:** During a Mycobacterium tuberculosis infection, Th1 cells secrete a factor capable of stimulating phagosome-lysosome fusion within macrophages. In addition, the secreted factors help activate macrophages to produce mediators such as NO, which are capable of destroying the invading pathogen. Furthermore, activation of the macrophages by the secreted factor eventually leads to the formation of a tubercle. Which of the following factors is secreted by Th1 cells and responsible for these actions?   (A) IL-4   (B) TNF-alpha   (C) IFN-gamma   (D) Histamine
['(C) IFN-gamma <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) IL-4 \n (B) TNF-alpha \n (C) IFN-gamma \n (D) Histamine <> possible answers', '  During a Mycobacterium tuberculosis infection, Th1 cells secrete a factor capable of stimulating phagosome-lysosome fusion within macrophages. In addition, the secreted factors help activate macrophages to produce mediators such as NO, which are capable of destroying the invading pathogen. Furthermore, activation of the macrophages by the secreted factor eventually leads to the formation of a tubercle. Which of the following factors is secreted by Th1 cells and responsible for these actions? <> context@']