"Surprising" Phenomenon
In forests that get a lot of acid rain, why are sugar maples more likely to show signs of decline consistent with calcium deficiency than are spruces or firs, even though all three kind of trees need calcium to survive and acid rain tends to lead to lower calcium levels in soil?
Objective
The correct answer will tell us about a difference between sugar maples and the other two kinds of trees that could lead to sugar maples being more likely to suffer from effects of calcium deficiency than are the other kinds of trees.
A
Soil in which calcium levels are significantly diminished by acid rain is also likely to be damaged in other ways by acid rain.
This doesn’t differentiate sugar maples from spruces and firs.
B
Sugar maples that do not receive enough calcium deteriorate less rapidly than spruces or firs that do not receive enough calcium.
This makes the discrepancy more difficult to explain, because it suggests sugar maples would be healthier than spruces and firs when they don’t get enough calcium. But sugar maples actually show more signs of decline.
C
Spruces and firs, unlike sugar maples, can extract calcium from a mineral compound that is common in soil and is not affected by acid rain.
This explains how spruces and firs can get more calcium than sugar maples, even when acid rain lowers levels of calcium in the soil. A non-soil source of calcium could lead to spruces and firs being less likely to suffer from calcium decline.
D
Sugar maples require more calcium in the spring and summer than they do in the fall and winter.
This doesn’t differentiate sugar maples from spruces and firs. We have no reason to think spruces and firs don’t have the same feature that this answer describes. So, we’re still left wondering why sugar maples are more likely to show signs of decline than the other trees.
E
Unlike spruces or firs, most sugar maples are native to areas that receive a lot of acid rain.
The stimulus compares sugar maples in forests that get a lot of acid rain with spruces and firs “in such forests.” So, we’re just talking about spruces and firs in forests that do get lots of acid rain.
Summarize Argument
The travel industry consultant concludes that these airlines are too concerned about the comfort of business class travelers and should instead prioritize the comfort of leisure travelers. He bases this on the fact that 80% of all airline tickets are purchased by leisure travelers.
Notable Assumptions
The travel industry consultant assumes that the comfort of leisure travelers is more important than the comfort of business class travelers, simply because leisure travelers purchase more tickets.
He also assumes that, just because leisure travelers purchase 80% of airline tickets overall, they also purchase 80% of tickets on each airline. It’s possible that the airlines that conducted these surveys are luxury airlines with far fewer leisure travelers than most airlines have.
He also assumes that, just because leisure travelers purchase 80% of airline tickets overall, they also purchase 80% of tickets on each airline. It’s possible that the airlines that conducted these surveys are luxury airlines with far fewer leisure travelers than most airlines have.
A
Business travelers often make travel decisions based on whether they feel a given airline values their business.
This may explain why airlines are working to improve business travelers’ comfort, but it doesn’t weaken the conclusion that airlines should instead focus on leisure travelers. We can’t assume that focusing on leisure travelers would make business travelers feel less valued.
B
Some airlines have indicated that they will undertake alterations in seating space throughout the entire passenger area of their planes in the near future.
We don't know what "alterations" means here. It could mean reducing space for leisure travelers to increase it for business travelers. Either way, (B) doesn't weaken the conclusion that airlines should prioritize leisure travelers over business travelers.
C
Sleeping in comfort during long flights is not the primary concern of leisure travelers.
It doesn’t matter what the primary concern of leisure travelers is. We need an answer choice that shows that just because they purchase 80% of all airline tickets doesn’t mean that leisure travelers’ comfort is more important than other passengers’ comfort.
D
A far greater proportion of an airline’s revenues is derived from business travelers than from leisure travelers.
(D) weakens the argument by implying that the assumption that leisure travelers’ comfort is more important because they purchase 80% of airline tickets is false. Just because they purchase more tickets, doesn’t mean that leisure travelers contribute more to airlines’ revenues.
E
Most leisure travelers buy airline tickets only when fares are discounted.
This doesn’t weaken the author’s conclusion because we don’t know how much these discounted fares affect airlines’ profits. The assumption remains that, just because leisure travelers purchase 80% of tickets, their comfort should be prioritized.