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
Diene's phenomenon is seen in 
Select and explain. 
A. Proteus, B. E.coli, C. Klebsiella, D. Mycoplasma
A: Proteus
Answer: A: Proteus 
Explanation: Diene's phenomenon - proteus
Diene's method of staining → mycoplasma