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
True about HACEK group of bacteria is ? 
Select and explain. 
A. Anaerobes, B. Includes coxiella burnetii, C. Grain positive, D. Require CO2 for growth
D: Require CO2 for growth
Answer: D: Require CO2 for growth 
Explanation: None