Step 1: Understand the Argument
Premise: Food cooked in iron pots absorbs significant amounts of iron during cooking. As a result, people whose food is cooked in iron pots consume enough iron this way to satisfy their nutritional requirements for iron.
Conclusion: Therefore, there is no need for these people to eat the kinds of foods that naturally contain iron.
Assumption: The argument assumes that the iron obtained from cooking in iron pots is sufficient for meeting nutritional needs, and that there is no other reason to consume foods naturally high in iron.
Step 2: Identify the Task
The question asks for the assumption on which the argument depends. In other words, we need to find an unstated premise that is necessary for the argument to hold true. If the assumption is not true, the argument would fall apart.
Step 3: Analyze Each Answer Choice
A. Food that has been cooked in iron pots does not absorb any non-nutritive elements from the pots.
Analysis: This choice focuses on whether non-nutritive elements are absorbed from the pots. While this could be relevant to the safety of cooking in iron pots, it does not address the argument's central claim about iron sufficiency. The argument is about meeting nutritional requirements for iron, not about other potential elements absorbed.
Conclusion: Not relevant to the argument.
B. Any essential nutrients other than iron in foods that naturally contain iron can be obtained from other foods.
Analysis: This choice addresses the possibility that foods naturally high in iron might contain other essential nutrients. If this were not true, then the argument would be weakened, as people might still need to consume these foods for reasons other than iron. This assumption is necessary for the argument to hold, as it rules out the need for these foods due to other nutrients.
Conclusion: This assumption is necessary for the argument.
C. People who prefer to use iron pots for cooking food do not use pots made of any other material.
Analysis: This choice focuses on whether people use only iron pots or also other types of pots. While this might be an interesting fact, it doesn't affect the core of the argument about whether iron from the pots can meet nutritional needs. The argument is concerned with the sufficiency of iron from the pots, not the exclusivity of their use.
Conclusion: Not relevant to the argument.
D. There are some foods that naturally contain as much iron as can be obtained from any other food that has been cooked in an iron pot.
Analysis: This choice compares the iron content in foods naturally high in iron to foods cooked in iron pots. While this might be true, it doesn't directly affect the argument about whether people need to eat foods naturally containing iron. The argument is concerned with whether the iron from cooking in pots is sufficient, not whether some foods contain more iron than others.
Conclusion: Not necessary for the argument.
E. The iron absorbed into food from iron pots is less easily digestible than the iron that occurs naturally in some foods.
Analysis: This choice suggests that the iron from the pots might be less easily digestible. If this were true, it would weaken the argument, as it implies that people might not absorb enough iron from food cooked in iron pots. However, the question asks for an assumption on which the argument depends. This choice is not an assumption, but rather something that would weaken the argument if true.
Conclusion: This is not an assumption; it would weaken the argument.
Step 4: Conclusion
The correct answer is B. Any essential nutrients other than iron in foods that naturally contain iron can be obtained from other foods.
Why? The argument claims that there is no need for people who cook in iron pots to consume foods naturally high in iron. However, if those foods contain other essential nutrients that cannot be obtained elsewhere, the argument would fail. Therefore, the assumption that these other nutrients can be obtained from other sources is necessary for the argument to hold.
Key Takeaways for Similar Questions:
Identify the core assumption: Determine what the argument depends on. Ask yourself, "What must be true for this conclusion to hold?"
Differentiate between necessary assumptions and weakening arguments: The correct assumption is something that the argument needs in order to be true. If negating the assumption would weaken the argument, then it's likely the correct answer.
Focus on relevance: Discard choices that introduce irrelevant details or focus on aspects of the situation that do not directly impact the argument