The transformation of arable or habitable land into land that is dry and no longer suitable for agriculture is called
a. desertification
b. deforestation
c. extinction
d. overgrazing

The answer is A. Desertification.

Explanation:

Desertification is a process of ecological degradation in which the fertile and productive soil totally loses the production potential, due to the result of deforestation and destruction of the vegetation cover, the subsequent erosion of the soils, the overexploitation of aquifers, over-irrigation and consequent salinization of the lands or lack of water. This process is mostly caused by the human being, which favors and increases this process as a result of activities such as excessive cultivation and grazing or deforestation.