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: Microbiology
The following diagnostic tests are useful for corresponding purposes except - 
Select and explain. 
A. Ziehl - Neelsen staining - Detection of mycobacteria, B. Immunofluorescence - Detection of Influenza virus, C. Specific IgM antibodies - Immunity against Rubella, D. Specific IgM antibodies - Detection of acute infection
C: Specific IgM antibodies - Immunity against Rubella
Answer: C: Specific IgM antibodies - Immunity against Rubella 
Explanation: For any infection (including rubella) IgM antibody alone, without IgG means current (acute) infection.


Ziehl Neelsen staining is used for mycobacteria.


Rapid diagnosis of influenza is made by demonstration of viral antigen in specimens by Immunofluorescence.