According to the text,which of the following stasement is NOT TRUE?
选项：

A:It is not easy to tell how“rock and roll”began.
B:Both the blues and country music were developed by the musicians in the southern United States.
C:Both the Europeans and the African slaves came to America during the 17th century.
D:It was the blues songs recorded in Memphis that made Elvis Presley popular throughout the world.