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
False statement about macrophages? 
Select and explain. 
A. Can harbor mycobacteria, B. Derived from blood monocytes, C. Involved in type III hypersensitivity reactions, D. Produce tumor necrosis factor and interleukins
C: Involved in type III hypersensitivity reactions
Answer: C: Involved in type III hypersensitivity reactions 
Explanation: Type III hypersensitivity occurs when there is an excess of antigen, leading to small immune complexes being formed that fix complement and are not cleared from the circulation. Large complexes can be cleared by macrophages but macrophages have difficulty in the disposal of small immune complexes. Macrophages are involved in type 3 hypersensitivity Reff: Anantharayan & Panikers textbook f microbiology 9th edition pg:166 www.mayoclinic.com