Final answer:
The third agricultural revolution, also known as the Green Revolution, is characterized by monocropping, where large-scale farms focus on cultivating single crops using advanced technology and significant chemical inputs.
Step-by-step explanation:
The characteristic of the third agricultural ("green") revolution is a) monocropping. This revolution entailed rapid technological innovation, large capital investments in equipment and technology, the emergence of large-scale farms, and reliance on monocultures or the cultivation of single crops. These practices were in conjunction with the adoption of uniform high-yield hybrid crops, dependency on agribusiness, mechanization, and extensive use of pesticides, fertilizers, and herbicides. The Green Revolution began in Mexico in the 1940s and had a profound impact on agriculture by developing high-response varieties of certain staple crops, expanding irrigation, and increasing the use of artificial fertilizers and pesticides, thus greatly enhancing food production.