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 soon decrease.
(B) Importing either grain or meat will not result in a significantly higher percentage of Gortlanders' incomes being spent on food than is currently the case.
(C) The per capita consumption of meat in Gortland is increasing at roughly the same rate across all income levels.
(D) The per capita income of meat producers in Gortland is rising faster than the per capita income of grain producers.
(E) People in Gortland who increase their consumption of meat will not radically decrease their consumption of grain.
Conclusion: Gortland will have to import either grain or meat or both.
Premise(s): As per capita income rises, so will per capita consumption of meat. It takes several pounds of grain to produce one pound of meat, and domestic grain production will not increase. So Gortland will have to import either grain or meat or both.
Prephrase: Let’s try to identify a possible assumption before answering the answer choices. It’s hard to identify one, so I think we’re working with a defender assumption. Let’s use the assumption negation technique and see which one weakens the argument the most. Using the assumption negation technique in the answer choices we can try and find the assumption on which the argument depends.
a) If grain production in Gortland will not soon decrease – Gortland will have to import either grain or meat or both. Thus, grain production in Portland will not increase, nor decrease, this keeps the premise intact and therefore doesn’t weaken the argument.
b) Importing either grain or meat will result in a significantly higher percentage of Gortlanders incomes being spent on food than is currently the case. Thus, food consumption will rise, therefore per capita consumption of meat is also likely to increase. Doesn’t weaken.
c) The per capita consumption of meat in Gortland is not increasing at roughly the same rate across all income levels. Thus different income levels have different levels of meat consumption. But it’s still increasing, so it still keeps the premises in check.
d) The per capita income of meat producers in Gortland is not rising faster than the per capita income of grain producers. The income of the meat producers themselves isn’t relevant. Therefore out of scope.
e) People in Portland who increase their consumption of meat will radically decrease their consumption of grain. If people in Portland decrease their consumption of grain, then Gortland will no longer have to import either grain or meat or both.
Therefore, answer choice E is correct. As it weakens the argument the most and is therefore the underlying assumption that holds the entire frigging thing together.