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: Anatomy
Which of the following agent of meningitis can grow on chocolate agar but not on blood agar? 
Select and explain. 
A. Neisseria meningitides, B. Haemophilus influenzae, C. Moraxella catarrhalis, D. Escherichia coli
B: Haemophilus influenzae
Answer: B: Haemophilus influenzae 
Explanation: H influenzae growns in the presence of factor X and V avaliable in blood. Factor V is intracellular hence not available easily. Also sheep blood contain NAdase thatdestroys factor V. In chocolate agar, blood is poured in molten agar which inactivates NADase and lyses RBCs releasing factor V.