Question ID:PT73 S2 Q20 Passage:The advent of chemical fertilizers led the farmers in a certain region to abandon the practice of periodically growing a "green-manure" crop, such as alfalfa, in a field to rejuvenate its soil. As a result, the soil structure in a typical farm field in the region is poor. So to significantly improve the soil structure, farmers will need to abandon the use of chemical fertilizers. Stem:The argument relies on the assumption that Correct Answer Choice:EChoice A:most, if not all, farmers in the region who abandon the use of chemical fertilizers will periodically grow alfalfa Choice B:applying chemical fertilizers to green-manure crops, such as alfalfa, has no positive effect on their growth Choice C:the most important factor influencing the soil quality of a farm field is soil structure Choice D:chemical fertilizers themselves have a destructive effect on the soil structure of farm fields Choice E:many, if not all, farmers in the region will not grow green-manure crops unless they abandon the use of chemical fertilizers