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
[{'content': 'Which one of the following statements best describes immunological tolerance? \nSelect and explain. \nA. Immunologic maturity of the host does not play a major role, B. It occurs only with polysaccharide antigens, C. It is related to the concentration of antibody, D. It is prolonged by administration of immunosuppressive drugs', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Whether an antigen will induce tolerance rather than an immunologic response is largely determined by immunological maturity of the host, structure, dose of antigen and administration of immunosuppressive drugs. Tolerance is best maintained by the presence of low concentrations of antigen. T cells become tolerant more readily than B cells.', 'role': 'assistant'}]