Over the last few years, Country A has suffered a pest infestation which has resulted in huge losses in agricultural yield. Since the infestation began, Country A’s imports have increased. Therefore, Country A will continue to import more than it did before the infestation started, and this will remain so until the infestation ends.
Remember we identified the components of this passage in the introductory article on argument-based passages. Now let us suppose that this passage appeared in your test with the following question-stem and possible answer choices:
Question: Which of the following, if true, most strengthens the argument presented in this passage?
A. The economy of Country A has traditionally relied on its agricultural exports.
B. Country A has encountered an electricity shortfall over the last few years, causing most of its tech industry to shut down which in turn has led to an inability for the local industry to meet the country’s growing demand for IT products.
C. The infestations have ravaged the entire countryside; not only are the food crops affected but the industrial crop has also been damaged.
D. A significant proportion of the recent infestation in Country A is caused by the boll weevil pest.
E. Because of the infestation, Country A, a country otherwise self-reliant in diet, has faced major shortages in staple foods in all parts of the country, and the situation does not seem to relent until the pest invasions cease.
Now if you recall the conclusion of the above passage:
Conclusion: Country A will continue to import more than it did before the infestation started, and this will remain so until the infestation ends.
The author reached this conclusion from the premises that Country A has incurred major losses in agricultural yield due to infestation, and that since the infestation began, an increase in imports has already been observed. In other words, the author is trying to argue that since the increase in imports coincides with the losses in yield due to infestation, it must therefore have been caused by and, by extension, end with the infestation itself.
To strengthen the argument, we have to select the option that further reinforces the following points on its own i.e. without requiring outside assumptions:
- The increase in Country A’s imports will stay this way.
- The increased amount of imports will not reduce until the infestation ends.
In other words, the increase in imports is directly tied to (or indeed caused by) the infestation. Let’s evaluate the answer choices to see if any of them strengthens this point.
Answer choice A states that the economy of Country A relies on agricultural exports. Does it have anything to do with the conclusion that the recent increase in imports was caused by infestation? Not really, it only points to a fact irrelevant to the conclusion of the passage. Even if the economy of Country A depends on agricultural exports, we still do not have enough evidence from the passage that the recent decrease in agricultural yield due to infestation is large enough to change the once exported items into imported ones. In any case, this answer choice does not naturally lead to the conclusion of the passage.
Answer choice B states that an electricity shortfall has also occurred over the last few years, which has dealt a blow to the country’s technology industry. This has led to an inability of the local tech industry to meet local demands. Does it prove that the recent increase in imports was due to the agricultural losses caused by infestation? No, in fact it suggests the opposite by pointing out another possible cause for the increase in imports.
Answer choice C only further elaborates the point that country has incurred considerable losses due to infestation by stating that the losses occurred in both food and non-food crops. However, to be the correct answer choice, it still requires the all-important outside assumption i.e. these losses are indeed the reason for the increase in imports and that there can be no alternative cause.
Answer choice D only specifies one of the pests involved in the infestation. Needless to say, it is irrelevant to the question stem i.e. it does not strengthen the causal relationship between the increase in imports and the infestation.
Answer choice E is the correct. It states that infestation has caused serious shortages in food all over the country (Notice the words Because of the infestation, which establish the causality). It also suggests that the situation will remain unchanged until the infestation ends and that before the infestation the country used to be self-reliant in food. By simply connecting the dots we can see that a ubiquitous crisis of food in a previously self-sufficient food growing nation should lead to a vital import that was previously not required and that this situation will continue for as long as the infestation continues.