The correct answer is knowing the ways that humans use Earth's natural resources.
The ancient settlers of the Andean region, at the foot of the Andes Mountains developed extraordinary irrigation and cultivation systems on the hillsides. The crops were deployed in the form of steps on the hillside making productive all the resources provided by nature and adding technology for its efficient and effective use.
The current farmers use some of the techniques and customs inherited from the original peoples and add the most modern technologies to further increase the productivity of the lands and contribute positively to the economy of their regions.
It is a common feature in the diverse cultures of humanity to adapt to the geographical characteristics of the region where they live solving the difficulties through ingenuity and hard work.
The correct answer is D) understanding the effect of places and regions on the people living in them.
In South America, some farmers build farms on hilltops because of the mountainous landscape. One of the Six Essential Elements of Geography that this most represent is "understanding the effect of places and regions on the people living in them."
The six essential elements of Geography are the world in spatial terms, places and regions, physical systems, human systems, environment and society, and uses of geography.
In this case, South American Indian civilizations such as the Incas had to find ways to overcome geographical difficulties because the region they lived in was mountainous. Indeed, they were great engineers that built homes at the top of the mountains and developed agriculture techniques that allowed to grow crops at the top of the mountains.
