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.
The Mongols, a tribe of Nomads from Central or North Asia, who were ruled by Genghis Khan at the time.
These deep-ocean<span> currents are driven by differences in the </span>water's<span> density, which is controlled by temperature (thermo) and salinity (haline). This process is known as thermohaline </span>circulation<span>. In the Earth's polar regions </span>ocean water<span> gets very cold, forming </span>sea<span> ice.</span>
