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: Dental
Micro organism which uses steroids as growth factor is 
Select and explain. 
A. P.gingivalis, B. P.intermedia, C. S.sanguis, D. S.mutans
B: P.intermedia
Answer: B: P.intermedia 
Explanation: None