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': 'Antibody diversity is due to -a) Gene rearrangementb) Gene translocationc) Antigenic variationd) CD40 moleculese) Mutation \nSelect and explain. \nA. ace, B. bde, C. cde, D. ade', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]