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': 'Borrelia undergoes antigenic variation due to: \nSelect and explain. \nA. Plasmids, B. Transposons, C. Intrinsic mutation, D. All of the above', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is. 'a' i. e., Plasmids", 'role': 'assistant'}]