[单项选择]　　Given that 8 percent of food crops grows faster on farms using groundwater than the aquifers are replenished, and many large rivers are so heavily diverted that they do not reach the sea for much of the year, researchers believe freshwater sources--underground aquifers and rivers--are stressed. Better management of soil and water and creative cropping patterns can boost production from rainfall-watered cropland, but the heaviest burden will fall on irrigated land. At present, most farmers irrigate their crops by channeling water down their fields in parallel furrows. 　　One alternative, drip systems, enables farmers to deliver water directly to the plants’’ roots drop by drop, nearly eliminating waste by distributing water at low pressure through a network of perforated plastic tubing installed on or below the surface of the soil, where it then emerges through small holes at a slow but steady pace. Because the plants enjoy an ideal moisture environment, drip irrigation usually offers
A. most North Americans would be unlikely to shift their diets simply in order to accommodate the exigencies of water conservation
B. the gains provided by diets with less water-intensive production would likely be less useful in areas with greater aquifer resources
C. people in Asia and certain European countries are dependent on meat-products and could not do without them
D. diets with less water-intensive production tend to be less healthy than those with more water-intense production
E. governments of certain countries would be unlikely to promote programs for diet change given their possible negative effect on those countries’’ economies