"Surprising" Phenomenon
Among workers who do similar amounts of typing, why do those who report the least control over their own work have a significantly higher risk of developing carpal tunnel syndrome as do those who report the most control?
Objective
The correct answer should help differentiate feeling the least control (or reporting the least control) from feeling the most control (or reporting the most control). This difference should provide a potential theory that could lead to those feeling the least control (or reporting the least control) to develop carpal tunnel syndrome at a higher rate.
A
Office workers who have the most control over their own work tend to do significantly less typing than do those who have the least control over their own work.
The stimulus already controlled for different amounts of typing: “among those who do similar amounts of typing...”
B
Feeling a lack of control over one’s own work tends to put one under emotional stress that makes one more susceptible to nerve disorders.
The stimulus told us carpal tunnel syndrome is a nerve disorder. If feeling lack of control can make one more susceptible to nerve disorders, this could account for why those reporting the least control get carpal tunnel syndrome (a nerve disorder) at a higher rate than those reporting the most control.
C
The keyboards on which office workers type tend to put typists’ arms and hands in positions that promote the development of carpal tunnel syndrome.
This doesn’t differentiate workers reporting the least control from those reporting the most. We have no reason to think workers reporting the least control are more likely to use the keyboards described in this answer.
D
Among office workers who rarely use keyboards, the rate of carpal tunnel syndrome is much higher for those who feel that they lack control over their own work.
The stimulus already controls for typing amount. Whether workers rarely use keyboards or use keyboards a lot, among those who do similar amounts of typing, people reporting the least control get carpal tunnel syndrome at a higher rate. Why? This answer doesn’t provide a theory.
E
Office workers who have the most control over their own work tend to perform repetitive motions other than typing more often than do office workers with the least control over their own work.
This makes the discrepancy more difficult to explain. If those who have the most control perform repetitive motions more than those who have the last control, we’d expect those who report feeling the most control to get carpal tunnel syndrome at a higher rate.
"Surprising" Phenomenon
Why did the human brain’s evolution take place almost entirely in the savnna and woodland rather than the shore, even though the food reources that could supply the high-calorie diet required for the brain’s development was more abundant in the shore?
Objective
The correct answer should help us differentiate the shore environment from the savanna and woodland in a way that could help explain why the brain’s development occurred in the savanna and woodland.
A
Early humans had a significantly lower metabolic rate than anatomically modern humans, allowing them to expend their fat reserves more efficiently.
This doesn’t differentiate the shore from the savanna and woodland. Even if early humans needed less fat, why did brain development occur in the savanna and woodland, which had less of the food resources required by the brain than did the shore? This doesn’t provide a theory.
B
The brains of the earliest known humans were 30 percent smaller than the anatomically modern human brain.
This doesn’t differentiate the shore from the savanna and woodland. Even if early humans had smaller brains, why did brain development occur in the savanna and woodland, which had less of the food resources required by the brain than did the shore? This doesn’t provide a theory.
C
Prehistoric savanna and woodland areas offered more reliable and abundant resources than they do today.
This compares savanna/woodland of the past to savanna/woodland of today. But it doesn’t compare the past savanna/woodland to the past shore environment. The stimulus still tells us that the past shore environment had more of the food resources than the past savanna/woodland.
D
The techniques used to explore the archaeology of prehistoric shore sites have only recently been developed.
This doesn’t suggest anything about the level of food resources available in the shore environment. Don’t assume that because the techniques were recently developed that we should doubt the facts given to us in the stimulus.
E
Gathering food in shore environments required a significantly greater expenditure of calories by early humans than did gathering food in other environments.
If it cost more in calories to gather food in the shore than it did to gather food in the savanna/woodland, this extra cost could have outweighed the benefit of more food in the shore. It’s possible overall calorie intake could be higher in the savanna/woodland than in the shore.