What do Tarbell and Rockefeller disagree about in these two readings?

What is the main idea of this excerpt

Which kind of map you would be used to show population density in the countries of the world

Which of the following explains why scarcity is a basic fact of life a. demand will always be greater than supply b. technology has not advanced far enough yet c. there will always be too many people on earth d. people cannot make good allocation decisions