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
HLA is the major histocompatibility antigen determining homograft rejection. This comes under 
Select and explain. 
A. Antigen specificity, B. Species specificity, C. Isospecificity, D. Auto specificity
C: Isospecificity
Answer: C: Isospecificity 
Explanation: HLA and blood groups come under iso-specificity in which antigens are present in ceain group of subjects in same species Ref: Textbook of Microbiology Baveja 5th ed Pg 94