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
[{'content': 'Reaction of soluble antigen with antibody is known as - \nSelect and explain. \nA. Agglutination, B. Precipitation, C. Flocculation, D. Complement fixation', 'role': 'user'}, {'content': "Answer: B \nExplanation: When a soluble antigen combines with its antibody in the presence of electrolytes at a suitable temperature and pH, the antigen-antibody complex form an insoluble precipitate. This is called precipitation reactions. Reference:Anathanarayan & paniker's 9th edition, pg no: 105 <\\p>", 'role': 'assistant'}]