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': 'A microbiologist wants to develop a vaccine for prevention of attachment of diarrhoeagenic E.coli to the specific receptors in the gastro-intestinal tract. All of the following fimbrial adhesions would be appropriate vaccine candidates except - \nSelect and explain. \nA. CFA-1, B. P1-Pili, C. CS-2, D. K 88', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]