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
Which one of the following bacteria is classified as facultative anaerobe ? 
Select and explain. 
A. Pseudomonas, B. Bacteroides, C. Escherichia, D. Clostridia
C: Escherichia
Answer: C: Escherichia 
Explanation: None