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
Mononuclear phagocytes are produced by - 
Select and explain. 
A. Thymus, B. Spleen, C. Bone marrow, D. Liver
C: Bone marrow
Answer: C: Bone marrow 
Explanation: The monocyte is formed in the bone marrow and transpoed by the blood ; it migrates into the tissues, where it transforms into a histiocyte or a macrophage. Reff: Ananthanarayanan & Panikers textbook of microbiology 9th edition pg:137