This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
Haemophilus parainfluenza requires which of the following factors 
Select and explain. 
A. Factor V, B. Factor X, C. Both factor V and X, D. Factor XI
B: Factor X
Answer: B: Factor X 
Explanation: Factor X has a group of heat stable compounds that synthesize enzymes like cytochrome and catalase involved in aerobic respiration. Since H influenza grows aerobically, it's needs it