A. William Harvey
B. Karl Landsteiner
C. Alexander Fleming
D. Joseph Lister
Explanation: Karl Landsteiner identified the major ABO blood groups, making safer blood transfusions possible.
A. William Harvey
B. Karl Landsteiner
C. Alexander Fleming
D. Joseph Lister
Explanation: Karl Landsteiner identified the major ABO blood groups, making safer blood transfusions possible.