Summary
Fluoride enters groundwater when rain dissolves minerals with fluoride in the soil. Researchers found that when all variables are held constant, fluoride concentrations are significantly higher in areas where the groundwater also contains a high concentration of sodium.
Strongly Supported Conclusions
When there is a high concentration of fluoride, there is likely a high concentration of sodium.
Sodium helps dissolve fluoride into groundwater.
Sodium helps dissolve fluoride into groundwater.
A
Fluoride-bearing minerals are not the primary source of fluoride found in groundwater.
The stimulus does not provide alternative sources of fluoride in groundwater
B
Rainfall does not affect fluoride concentrations in groundwater.
This is anti-supported. The stimulus explains that rainfall causes minerals with fluoride to dissolve and enter the groundwater
C
Sodium-bearing minerals dissolve at a faster rate than fluoride-bearing minerals.
There is no information in the stimulus to support this comparative statement. There is no information about the rate at which sodium vs fluoride dissolves
D
Sodium in groundwater increases the rate at which fluoride-bearing minerals dissolve.
The stimulus explains that fluoride concentrations are higher in areas with high sodium concentrations, even when all variables are held constant. This suggests that the sodium could impact the rate at which minerals with fluoride dissolve.
E
Soil that contains high concentrations of sodium-bearing minerals also contains high concentrations of fluoride-bearing minerals.
This has the logic flipped. It is conceivable that high concentrations of fluoride minerals are found in areas with high concentrations of salt, not the other way around.
Summarize Argument: Counter-Position
Fraenger asserts that Bosch belonged to the Brethren of the Free Spirit. The author concludes that this is unlikely to be correct. This is based on the fact that Bosch was a member of a mainstream church, and there’s no evidence that he was a member of the Brethren.
Identify Argument Part
The referenced text is offered to support the conclusion that Bosch probably didn’t belong to the Brethren of the Free Spirit.
A
It is a premise that, when combined with the other premises, guarantees the falsity of Fraenger’s assertion.
This is too extreme. The premises do not guarantee that Fraenger’s assertion is false.
B
It is used to support the claim that Bosch was a member of a mainstream church.
The referenced text does not support the claim that Bosch was part of a mainstream church. It is used in combination with that claim to support the conclusion that Bosch probably didn’t belong to the Brethren of the Free Spirit.
C
It is used to dispute Fraenger’s hypothesis by questioning Fraenger’s credibility.
The author doesn’t question Fraenger’s credibility. She questions the support for Fraenger’s assertion.
D
It is intended to cast doubt on Fraenger’s hypothesis by questioning the sufficiency of Fraenger’s evidence.
This accurately describes the role of the claim that there’s no evidence Bosch was a member of the Brethren. By pointing out there’s no evidence, the author questions whether there is enough evidence to support Fraenger’s assertion.
E
It is intended to help show that Bosch’s choice of subject matter remains unexplained.
Although Bosch’s choice of subject matter may be unexplained, the author doesn’t offer the referenced text to help show this. It’s offered to support the claim that Bosch probably didn’t belong to the Brethren of the Free Spirit.