The reasonable measures to control the ecological environment of the Loess Plateau are: ① building terraces on the slope to slow down the slope; (2) Accelerate the construction of forest land and regulate the surface runoff; (3) Planting trees and grass to improve vegetation coverage; (4) Building warping dams to store water and stop sand in low-lying areas; ⑤ Control the number of livestock grazing. The analysis topic is easy to get: vigorously developing animal husbandry in the loess plateau will cause more serious soil erosion, which is not desirable, and ABC measures are conducive to improving the ecological environment of the loess plateau.
Therefore, choose: d.