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#36774
Complete Question Explanation

Flaw in the Reasoning—CE. The correct answer choice is (B)

This stimulus provides a definition of the term “tidal range,” followed by information about one
particularly large one. The author then makes the following causal argument:
  • Premise: The only forces involved in causing tides are gravitational in nature.

    Conclusion: Thus the magnitude of tidal ranges must be entirely caused by those same
    gravitational forces.
Note that the argument jumps from a premise that deals with the cause of tides to a conclusion about the
cause of the magnitude of tidal ranges. That leap is unjustified; although tides are induced by gravity,
tidal range size may be affected by other factors. Since the question asks us to identify the flaw, we
should look for a response that discusses this leap (or any answer choice that points out the failure to
consider alternative causes of a tidal range’s magnitude).

Answer choice (A): The use of only one example is not a flaw in the reasoning; the example was used
to illustrate how big tidal ranges can get, so more examples wouldn’t be necessarily required in this
context.

Answer choice (B): This is the correct answer choice, as it points out the author’s failure to consider
other conditions (alternative causes) that might affect the size of a tidal range.

Answer choice (C): The author discusses what causes the actual magnitude of tidal ranges, not their
measurement. This choice does not describe a flaw, so it is incorrect.

Answer choice (D): The author does not discuss most activity in the world’s oceans, only tides and tidal
ranges, so this choice is wrong.

Answer choice (E): Since the argument concludes only that gravitational forces account for the
magnitude of tidal ranges, it is not important to differentiate between the tidal effects of the moon’s
gravity and those of the sun’s.

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