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
PK reactio detects - 
Select and explain. 
A. IgG, B. IgA, C. IgE, D. IgM
C: IgE
Answer: C: IgE 
Explanation: The Prausnitz-Kustner test (PK test, Prausnitz-Kustner reaction) is an immunologic test formerly used by physicians to determine if a patient has an allergic reaction to a specific antigen i.e, IgE Ref: Ananthanarayan & Parkers textbook of microbiology 9th edition pg:98