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
Who introduced the vaccination for smallpox? 
Select and explain. 
A. Edward Jenner, B. Louis Pasteur, C. Mathieu Orfila, D. John snow
A: Edward Jenner
Answer: A: Edward Jenner 
Explanation: "Edward Jenner introduced vaccination for smallpox with cowpox virus in 1798" Ref: Ananthanarayanan, 7/e, Page 5-7