C) Western expansion spread the U.S population over a wider area.
The main goal of UNESCO is t<span>o end extreme poverty around the world.
UNESCO is an organization based in PAris that stands for </span><span>The United Nations Educational, Scientific and Cultural Organization , and it's aimed to end the world's proverty through the exchange of education, scientifc, and cultural objects from one nations to another in order to make a sense of belonging to grow within nations.</span>
The right option is; a. soil degradation
Soil degradation most plausibly accounts for the reduction in corn yield.
Soil degradation is an environmental problem in which the condition or quality of soil is reduced due to its improper use usually for agricultural or industrial purposes. Soil degradation can reduce the physical, chemical and biological quality of soil. Soil degradation results in loss of organic matter, soil contamination, fertility decline, and soil acidity or alkalinity which can greatly affect agricultural productivity.
