Critical Reasoning

Gortland has long been narrowly self-sufficient in both grain and meat. However, as
per capita income in Gortland has risen toward the world average, per capita
consumption of meat has also risen toward the world average, and it takes several
pounds of grain to produce one pound of meat. Therefore, since per capita income
continues to rise, whereas domestic grain production will not increase, Gortland will
soon have to import either grain or meat or both.
Which of the following is an assumption on which the argument depends?
A. The total acreage devoted to grain production in Gortland will not decrease
substantially.
B. The population of Gortland has remained relatively constant during the
country's years of growing prosperity.
C. The per capita consumption of meat in Gortland is roughly the same across all
income levels.
D. In Gortland, neither meat nor grain is subject to government price controls.
E. People in Gortland who increase their consumption of meat will not radically
decrease their consumption of grain