B应改是不对的,因为题中说since per capita income continues to rise,那么按照我们的白痴做题员则,即使最后人口降到1个人,可是income一直增张,那么还是有一天meat 和 grain会不够的,但对E还是有点不明白,因为即使最后Grain不用进口了,可是原文中并没有说Grain是制作meat的唯一材料,也就是说最后还是有可能因为起他原因而造成meat不足,(比如说没有足够的牛了),如果这样,虽然说不用进口Grain,可还是要进口Meat,这也就是原文的结论(either grain or meat)
1. per capita income=> "population" and "per capita consumption across all income levels" is irrelavent, so B, C are not correct. 2. Government control also seems irrelavent, otherwise Gmat would be like a economic theory test. So D is also wrong. 3. per capita income (C)=per capita production of grain (A) + per capita production of meat (B), so if A will not increase, in order to let C increase (the last sentence of question), B must increase, AND ALSO A MUST NOT DECREASE, otherwise it will set off the amt B increased... So only E is correct.