Bunuel wrote:
During the production of orange juice, calcium is sometimes added as a nutritional supplement. Certain individuals are allergic to calcium, and drinking orange juice fortified with calcium can cause an allergic reaction. Fortunately, some types of orange juice do not have calcium added during production, so calcium-allergic individuals can drink these orange juices without inducing an allergic reaction to calcium.
Which of the following is an assumption on which the argument depends?
(A) There are no other substances besides calcium that are typically present in orange juice that cause allergic reactions.
(B) Orange juice has the same nutritional value whether calcium is added or not.
(C) Calcium-allergic individuals cannot ingest any calcium without having an allergic reaction.
(D) Calcium is often added to other beverages besides orange juice.
(E) In orange juice that does not have calcium added during production, calcium is not naturally present in quantities that cause an allergic reaction.
OFFICIAL EXPLANATION
Unlike Supporter assumptions, Defender assumptions can be extremely hard to prephrase because there are so many possibilities for the test makers to choose from. The correct answer in this problem is a Defender, but you should not feel bad if you could not predict the answer. The previous problem (a Supporter Assumption question) is perhaps more conducive to prephrasing.
In this stimulus, the author points out that orange juice sometimes has calcium added as a nutritional supplement, but that calcium causes an allergic reaction in some people. Based on the fact that orange juice is also available with no calcium added, the author concluded that this type of juice can be safely consumed by those with a calcium allergy.
The stimulus is followed by an Assumption question. Since there is no “missing link” in this case, we can see that this is a Defender Assumption question. If we do not have a prephrased answer for this one, we should assess the choices until we find an assumption that the author’s argument requires.
Answer choice (A): The author does not conclude that orange juice is free of all allergens—the far more limited conclusion present in the stimulus is that people who are allergic to calcium could safely consume orange juice that has not had calcium added.
Answer choice (B): The nutritional value of orange juice is not at issue in this question, and the argument does not require this assumption.
Answer choice (C): This choice simply provides that people who are allergic to calcium are very allergic. That is, any amount will trigger an allergic reaction. Since the author’s conclusion indicates that non-calciumadded orange juice is safe for such people to consume, this is not an assumption on which the argument relies.
Answer choice (D): This choice is outside the scope of the issue under discussion. The author’s comments are limited to orange juice and its safety for people who are allergic to calcium. The existence of other calcium supplemented products is irrelevant, so this is not an assumption on which the author’s argument relies.
Answer choice (E): This is the correct answer choice, and an assumption that is required of the author’s argument. The author must be assuming that orange juice has no naturally present calcium—if it does have some calcium naturally that would cause an allergic reaction, then this would destroy the author’s conclusion that, as long as calcium has not been added, calciumallergic people could safely drink orange juice.
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