All of these are factors in the growth of the presidency
The president increase visibility due to the development of the mass media.
The new deal and other programs her expanded federal responsibility.
Americans increase prominence in international affairs.
Canefight! Preston Brooks and Charles Sumner!
The question is asking to determine what continent is not yet touched by the European explorers, and i would say that the answer would be that they explored every continent and the last one of them is Antartica. I hope you are satisfied with my answer and feel free to ask for more