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
Antigen binding site on antibody is - 
Select and explain. 
A. Hinge region, B. Constant region, C. Variable region, D. Hypervariable region
C: Variable region
Answer: C: Variable region 
Explanation: The antigen combining site of the immunoglobulin molecule is at its amino terminus. - it is composed of both L and H chains. - the first 110 amino acid from the N terminal is quite variable in amino acid sequence and this region is called the variable region: Variable light chain and variable heavy chain. Reference: Anathanarayan & paniker&;s 9th edition, pg no: 94 <\p>