Question

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.

Hint:

The Negation Test is one of the most powerful tools for "Assumption" questions. A necessary assumption is a statement that the author must believe is true to draw their conclusion. If you logically reverse it (negate it) and the argument no longer makes sense, you've found the correct answer.

Answer 1

Answer: (E)

Step 1: Understanding the Argument
The argument concludes that Gortland will soon need to import food (grain or meat).
Chain of Reasoning: \begin{enumerate} \item Rising income leads to rising meat consumption. \item Producing meat requires a lot of grain as feed. \item Therefore, as meat consumption rises, the total demand for grain (for animal feed + for human consumption) will also rise. \item Domestic grain production is static (will not increase). \item Therefore, total grain demand will soon exceed domestic grain supply. \item This will create a shortfall that must be met by importing either the final product (meat) or the raw material (grain). \end{enumerate}

Step 2: Analyzing the Task
We need to find a necessary assumption. An assumption is an unstated premise that must be true for the conclusion to be valid. A good way to test for a necessary assumption is the "Negation Test." If we negate the correct answer choice, the entire argument should fall apart.

Step 3: Evaluating the Options and Applying the Negation Test
(A) The argument only requires that grain production not increase. A decrease is not necessary. Negation: "The total acreage... will NOT soon decrease." The argument still holds.
(B) The argument is about the need to import, not the economic consequences of importing. The conclusion can be true even if importing is very expensive. Negation: "Importing will result in a significantly higher percentage of income being spent on food." This doesn't affect the fact that the import is necessary.
(C) The argument depends on the average per capita consumption of meat increasing. How this increase is distributed among the population is irrelevant to the national total. Negation: "Meat consumption is increasing at very different rates." The argument still holds as long as the average is rising.
(D) The income of producers is irrelevant to the consumption patterns of the nation as a whole. The argument still holds regardless of producer incomes.
(E) This option addresses a potential loophole in the argument. The argument assumes that the increase in grain needed for animal feed will lead to an overall increase in total grain demand. But what if people who eat more meat also eat less grain directly (e.g., they eat a steak instead of a bowl of pasta)? This choice assumes that this substitution effect is not large enough to cancel out the increased demand for animal feed.
Negation Test: Let's negate option (E). "People in Gortland who increase their consumption of meat WILL radically decrease their consumption of grain." If this is true, then the increase in demand for grain for animal feed could be completely offset, or even outweighed, by the sharp decrease in demand for grain for direct human consumption. If the total net demand for grain does not increase, then Gortland's static production might remain sufficient, and the conclusion that they must import would no longer be valid. Since negating this statement breaks the argument, it is a necessary assumption.
Step 4: Final Answer
Option (E) is the correct answer. It is a necessary assumption because it closes the logical gap by ensuring that the shift in diet towards more meat results in a net increase in the country's total grain requirements.