Question

Which was not a result of the 1898 discovery of the four blood types and advances made during the two World Wars?
improved blood transfusion safety
effective blood preservation solutions developed
ability to separate different parts of blood for different uses
all blood types were made universally compatible

Answer 1

"all blood types were made universally compatible" — that did NOT result. Transfusion safety, preservation solutions, and blood component separation were achieved, but blood types still must be matched (though O negative is a limited "universal donor" for red cells).