Prep的一道逻辑题，求大神点解啊～～～

FloraZhang1228

The country of Baurisia has, until now, been self-sufficient in both grain and meat. However, with growing prosperity in Baurisia has come a steadily increasing per capita consumption of meat, and it takes several pounds of grain to produce one pound of meat. Therefore, since per capita income in Baurisia is almost certain to rise further but increases in domestic grain production are highly unlikely, Baurisia is soon likely to become an importer of grain.

Which of the following, if true, most seriously weakens the argument?

• A When people increase their consumption of meat, they also tend to increase their consumption of grain.  分析A选项
• B The per capita consumption of meat in Baurisia is roughly the same across all income levels.  分析B选项
• C Per capita consumption of meat has not increased substantially in recent years in those countries from which Baurisia is likely to import meat.  分析C选项
• D It is more economical for Baurisians to import meat than grain.  分析D选项
• E During Baurisia's years of growing prosperity, the country's population has remained relatively stable.  分析E选项
  

正确答案是D，但是B为啥不对呢？削弱前提 - 收入升高，肉的消耗增多

alzn2765

B选项里哪个单词提到“收入升高”了？