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': 'Non gonococcal urethritis is mostly caused by: \nSelect and explain. \nA. Chlamydia and streptococcus, B. Chlamydia and ureaplasma, C. Chlamydia and treponema, D. Chlamydia and mycoplasma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Chlamydia and ureaplasma', 'role': 'assistant'}]