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': 'Antigen antibody precipitation is maximally seen in which of the following ? \nSelect and explain. \nA. Excess of antibody, B. Excess of antigen, C. Equivalence of antibody and antigen, D. Antigen Hapten interaction', 'role': 'user'}, {'content': "Answer: C \nExplanation: According to lattice hypothesis, precipitation results when a large lattice is formed consisting of alternating antigen and antibody molecules. This is possible only at the zone of equivalence. At the zone of equivalence, antigen and antibody are in optimum propoion. Lattice formation and visible reactions are enhanced. Reference: Anathanarayan & paniker's 9th edition, pg no:105 <\\p>", 'role': 'assistant'}]