In the United States proven oil reserves—the amount of oil considered extractable from known fields—are at the same level as they were ten years ago. Yet over this same period no new oil fields of any consequence have been discovered, and the annual consumption of domestically produced oil has increased.
Which one of the following, if true, best reconciles the discrepancy described above?
[A]. Over the past decade the annual consumption of imported oil has increased more rapidly than that of domestic oil in the United States.
[B]. Conservation measures have lowered the rate of growth of domestic oil consumption from what it was a decade ago.
[C]. Oil exploration in the United States has slowed due to increased concern over the environmental impact of such exploration.
[D]. The price of domestically produced oil has fallen substantially over the past decade.
[E]. Due to technological advances over the last decade, much oil previously considered unextractable is now considered extractable.
Answer: E
Explanation:
The question stem tells us there’s a discrepancy at work in this one, so immediately we should be on the alert for something that doesn’t seem to add up. Hopefully, you had no problem spotting the supposed inconsistency detailed in the short stimulus. Pared down, here’s the strange situation: The amount of oil in U.S. proven oil reserves is the same as ten years ago, but oil consumption has increased. One possible explanation is ruled out—no new oil fields have been discovered. So where’s the extra oil coming from? (E), if true, solves the mystery: It’s coming from the same proven oil reserves. Thanks to technological advances, these oil fields can now turn out more oil, because some oil previously thought to be unextractable is now considered extractable. “Proven oil reserves” are explicitly defined as the amount of oil “considered extractable from known fields.” “Considered” here is the key:
If this consideration has changed in the way noted in (E), then it’s no longer surprising that the proven oil reserves are at the same level as ten years ago even though consumption continues to increase. (E) thus reconciles the apparent discrepancy.
(A) presents an irrelevant comparison. Since the passage—and the supposed discrepancy contained therein—is based exclusively on the level and consumption of domestic oil, any comparison of domestic oil to imported oil has no bearing on the argument.
(B) So what if the rate of growth is declining? The fact that consumption is still growing (albeit at a slower rate) preserves the mystery. If consumption is growing at all (no matter how slowly it’s growing compared to ten years ago), and if there are no new wells, how is it that the oil level is the same as ten years ago? (B) doesn’t help us resolve the discrepancy.
(C) The only possible thing (C) helps explain is why there have been no new oil fields discovered recently. As for the seeming discrepancy at hand, no help.
(D) Price? Like (C), (D) offers a possible explanation for a single element of the argument, in this case, the increased annual consumption of oil. The issue here is the amount, or level, of oil, and a decrease in price by itself, while possibly a factor in the increased consumption (maybe the decreased price has driven the increased consumption), still has no effect on the surprising amount of oil in the U.S. reserves.
To resolve a seeming discrepancy or apparent paradox, the correct choice must hit at the central element of the unusual or surprising finding or result. Here, the concept of “amount” is at the heart of the mystery: Given the circumstances, how could there be the same level of oil now as there was ten years ago? (E) hits at that issue by strongly suggesting that a greater amount of oil from the proven wells now fits the definition in the first sentence. Conversely, choices focusing on other kinds of oil (A) and price (D) can’t help us, and should have been easy choices to axe.
As mentioned above, (C) and (D) offer possible explanations for certain facts in the stimulus. But that’s not enough; we’re looking for a choice that resolves the discrepancy. Don’t get sucked into a choice just because it’s relevant to something—the correct choice has to be relevant to the task stated in the stem, which in this case is to reconcile the apparent discrepancy.
Definitions are key. If the testmakers go out of their way to define a phrase or term, make sure you keep that definition in mind. Often, noticing such a definition and taking account of it accordingly will be the key to getting the point. Sure, this seems like a strange situation—U.S. oil is at the same level as it was ten years ago while demand and consumption have increased—but when we focus on the fact that oil level in this case is strictly defined as the amount considered extractable, it become easier to see how (E) helps explain away the seeming discrepancy.
