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 reaction that occurs when antibody and soluble antigen are mixed is demonstrated by the 
Select and explain. 
A. Agglutination test, B. Precipitin test, C. Hemagglutination test, D. None of the above
B: Precipitin test
Answer: B: Precipitin test 
Explanation: In precipitation test, antibody combines with soluble antigen. While in agglutination test, antibody combines with insoluble antigen