This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: general microbiology, Subject name: Microbiology
Griffith demonstrated transformation with - 
Select and explain. 
A. H. influenzae, B. E. coli, C. Proteus, D. Pneumococcus
D: Pneumococcus
Answer: D: Pneumococcus 
Explanation: Griffith in 1928 found that mice died when injected with a mixture of live non-capsulated (R) pneumococci and heat killed capsulated (S) pneumococci, neither of which separately proved fatal. REF:Ananthanarayan and Panicker's Textbook ofMicrobiology 8thEdition pg no:63