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
A 30 year old male patient presents with urethritis. All of the following can be the causative agent except- 
Select and explain. 
A. Neisseria gonorrhoeae, B. Chlamydia trachomatis, C. Trichomonas vaginalis, D. Haemophilus ducreyi
D: Haemophilus ducreyi
Answer: D: Haemophilus ducreyi 
Explanation: Hemophilus ducreyi can cause genital ulcer but not urethritis