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
Culture medium used for streptococcus pneumoniae 
Select and explain. 
A. Human blood agar, B. Sheep blood agar, C. MacConkey's agar, D. Deoxycholate agar
B: Sheep blood agar
Answer: B: Sheep blood agar 
Explanation: Sheep blood agar