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

Explanation:

The discovery of four blood - types and advancements during the World Wars improved blood transfusion safety, allowed for separation of blood parts, and led to development of preservation solutions. But all blood types are not made universally compatible.

Answer:

A. all blood types were made universally compatible