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
Most common cause of Non gonococcal urethritis is - 
Select and explain. 
A. Meningococci, B. E. coli, C. Chlamydia trachomatis, D. Mycoplasma
C: Chlamydia trachomatis
Answer: C: Chlamydia trachomatis 
Explanation: None