"Surprising" Phenomenon
Toning shoes don’t exercise leg muscles more than regular shoes, yet most people who switch to toning shoes experience a strengthening of their leg muscles.
Objective
The correct answer will be a hypothesis that explains a key difference between toning shoes and regular shoes, beyond the actual exercise the shoes afford. This difference likely rests in who wears the shoes. People may, for example, experience a strengthening of their leg muscles after switching to toning shoes because they’re making a concerted effort to get exercise.
A
Toning shoes strengthen small underused muscles in the feet and ankles.
We’re concerned with how major leg muscles are strengthened.
B
Muscles in the leg adapt to the rounded shape of toning shoes almost immediately.
This reinforces the idea that toning shoes provide no exercise benefit. We need to know why people who switch to them get a benefit, anway.
C
Many people find toning shoes especially comfortable and walk more as a result.
True, toning shoes don’t have any real exercise advantage over regular shoes. But people who switch to toning shoes end up walking more, which certainly exercises their leg muscles. This explains how they get a benefit from toning shoes.
D
There is little evidence that toning shoes cause injuries to their wearers.
Our stimulus says nothing about injuries. We need to know why people who switch to toning shoes get a benefit.
E
Shoes that strengthen the major leg muscles are more marketable than ordinary shoes.
Toning shoes don’t themselves strengthen the major leg muscles.
Summarize Argument: Phenomenon-Hypothesis
The scientists hypothesize that humans, who arrived just before the last ice age ended, caused sloths to start disappearing from the Americas around 10,000 years ago and eventually to go extinct. This is supported by the fact that humans’ arrival and sloths’ disappearance happened around the same time.
Notable Assumptions
The scientists assume that humans could have caused the extinction of all giant ground sloths worldwide. They also assume that there are no alternative hypotheses, like other predators, natural disasters, or disease, to explain the sloths’ disappearance.
A
Scientists have not found any physical evidence to support the idea that giant ground sloths were hunted to extinction.
This weakens the argument by suggesting that humans may not have been responsible for sloths’ extinction, since no physical evidence of hunting has been found.
B
Species of smaller tree-dwelling sloths continue to live throughout South and Central America.
The scientists’ argument only addresses giant ground sloths that did go extinct. The survival of other kinds of sloths is irrelevant.
C
Their large size made the giant ground sloths less adaptable than most other ground mammals.
This weakens the argument by suggesting that the scientists’ original hypothesis- that giant ground sloths failed to adapt to climate changes- may have been correct after all.
D
Giant ground sloths are not the only large mammals that began to disappear from the Americas around 10,000 years ago.
This fails to address the cause of the giant ground sloths’ disappearance. Even if other large mammals also began disappearing at the same time, (D) doesn’t strengthen the hypothesis that humans are responsible for these disappearances.
E
One type of giant ground sloth survived on isolated islands until human beings arrived there well after the last ice age.
Some giant ground sloths survived long after the last ice age, meaning they didn’t disappear due to climate changes. These sloths only disappeared after humans arrived, which strengthens the hypothesis that humans were responsible for their extinction.