It's #1. Hope the answer helped.
The correct answer is - carving terraced farmlands.
The Incas revolutionized the agriculture in South America by starting to use the carved terraces for production. With this technique, the Incas managed to maximize the arable land area, and to perform farming on places where naturally will be impossible. This method is widely used nowadays, and since the amount of arable land is reducing in the lowlands, it is of great benefit for food production in places that are not suitable for building.
Humans affect the physical environment in numerous ways: overpopulation, contamination, burning fossil powers, and deforestation. Changes like these have triggered climate alter, soil erosion, poor air quality, and undrinkable water. These negative impacts can influence human behavior and can provoke mass migrations or battles over clean water.
Troposphere is the layer closest to earth, which includes the air that we breathe. After this comes the Stratosphere which includes the ozone layer and then the Mesosphere. After this it's the thermosphere and then the exosphere.
The one I didn't mention is the methosphere - this is the correct answer!
A. Decomposers
Decomposers turn organic wastes, such as decaying plants, into inorganic materials, such as nutrient-rich soil.
