Critical Reasoning

Ecologist: The Scottish Highlands were once the site of extensive forests, but these
forests have mostly disappeared and been replaced by peat bogs. The common view is
that the Highlands' deforestation was caused by human activity, especially agriculture.
However, agriculture began in the Highlands less than 2,000 years ago. Peat bogs,
which consist of compressed decayed vegetable matter, build up by only about one foot
per 1,000 years and, throughout the Highlands, remains of trees in peat bogs are
almost all at depths great than four feet. Since climate changes that occurred between
7,000 and 4,000 years ago favored the development of peat bogs rather than the survival
of forests, the deforestation was more likely the result of natural processes than of human
activity.


In the ecologist's argument the two portions in boldface play which of the following
roles?
A. The first is evidence that has been used in support of a position that the ecologist
rejects; the second is a finding that the ecologist uses to counter that evidence.
B. The first is evidence that, in light of the evidence provided in the second, serves
as grounds for the ecologist's rejection of a certain position.
C. The first is a position that the ecologist rejects; the second is evidence that has
been used in support of that position.
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D. The first is a position that the ecologist rejects; the second provides evidence in
support of that rejection.
E. The first is a position for which the ecologist argues; the second provides
evidence to support that position.

Premise : The scottish highlands were once the site of extensive forests.
These forests have disappeared and replaced by peat bogs.
The common view is that deforestation was caused by human activity especially agriculture.

Counter premise : Boldface1 However agriculture began in the high lands less than 2000 years ago.
Peat Bogs build up only about one foot per 1000 years
Boldface 2 Remains of trees in these peat bogs are all at depths more than 4 feet.
climate changes occurred between 7000 and 4000 years ago.

Conclusion : Therefore deforestation was more likely the result of natural process (climate changes) than human activity (agriculture)

A. The first is evidence that has been used in support of a position that the ecologist rejects; the second is a finding that the ecologist uses to counter that evidence.
Incorrect : 'Finding' is not mentioned in the passage above. Hence Eliminated.

B. The first is evidence that, in light of the evidence provided in the second, serves as grounds for the ecologist's rejection of a certain position.
Correct : The author tries to reject the position that deforestation was caused by human activity. He does that by providing counter premises Boldface 1 and Boldface 2.

C. The first is a position that the ecologist rejects; the second is evidence that has been used in support of that position.
Incorrect : The author certainly DOES NOT reject boldface 1. Eliminated.

D. The first is a position that the ecologist rejects; the second provides evidence in support of that rejection.
Incorrect : --------- Same as C ----------------

E. The first is a position for which the ecologist argues; the second provides evidence to support that position.
Incorrect : The author does not ARGUE boldface 1.

A. The ecologist rejects the common view about the Highlands' deforestation. The first claim supports main claim. After all, "however" indicates a change in direction.
B. Correct. First and second bold support main claim, "rejection of a certain position."
C. First bold face is not the position that the ecologist rejects.
D. First bold face is not the position that the ecologist rejects.
E. The first is not the ecologist's argument; it is evidence.