This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: miscellaneous, Subject name: Microbiology
[{'content': 'Most common cause of Non-gonococcal urethritis is \nSelect and explain. \nA. Meningococci, B. Escherichia coli, C. Chlamydia trachomatis, D. Mycoplasma', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The most common cause of non-gonococcal urethritis is C.trachomatis. Other common organisms are ureaplasma ureolyticum and Mycoplasma hominis. Ref: Ananthanarayan and Paniker&;s Textbook of Microbiology, 9th edition; pg no: 234', 'role': 'assistant'}]