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
Specific immunological unresponsiveness is called tolerance. Which one of the following statements best describes immunological tolerance- 
Select and explain. 
A. 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 immuno-suppressive drugs
D: It is prolonged by administration of immuno-suppressive drugs
Answer: D: It is prolonged by administration of immuno-suppressive drugs 
Explanation: None