This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
Which of the following metabolizes arginine? 
Select and explain. 
A. Mycoplasma pneumoniae, B. Mycoplasma genitalium, C. Mycoplasma hominis, D. Ureaplasma urealyticum
C: Mycoplasma hominis
Answer: C: Mycoplasma hominis 
Explanation: M. hominis metabolizes arginine, with the production of potentially cytotoxic amounts of ammonia. Ureaplasmas have been placed in a separate genus because of their unique urease activity; the metabolism of urea also produces ammonia.