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
Variable poion of antibody molecule is - 
Select and explain. 
A. C-terminal, B. N-terminal, C. Intermediate region, D. Carbohydrate moiety
B: N-terminal
Answer: B: N-terminal 
Explanation: Question repeated