16Hit1600
Craft and StructureVery hardText Structure and Purpose: function of an underlined sentence within an argument

Craft and Structure practice question

In 2019, geochemist Mira Okonkwo analyzed sediment cores from a West African crater lake to reconstruct regional rainfall over the past two millennia. Her data indicated a prolonged dry interval overlapping with the decline of several Sahelian trading centers, a correspondence that historians quickly cited as evidence of climate-driven collapse. Okonkwo herself has been more circumspect. Her cores, she notes, register regional averages at decadal resolution, whereas the abandonment of any given settlement unfolded over a few years and depended on local water management, trade routes, and political succession. The reconstruction, in other words, can establish that conditions changed but not that a particular community failed because of that change.

Which choice best describes the function of the sentence "Okonkwo herself has been more circumspect" in the text as a whole?

  1. A. It marks a shift from the sweeping interpretation others have drawn from Okonkwo's data to Okonkwo's own narrower account of what those data can demonstrate.Correct
  2. B. It concedes that Okonkwo's dating methods are less precise than those relied on by the historians who cite her work.
  3. C. It introduces a dispute among geochemists about how sediment cores from crater lakes should be interpreted.
  4. D. It indicates that Okonkwo has revised the conclusions she originally drew from her sediment cores.

Answer: A. It marks a shift from the sweeping interpretation others have drawn from Okonkwo's data to Okonkwo's own narrower account of what those data can demonstrate.

Correct (A): The sentence pivots the text. Before it, historians read the rainfall–decline overlap as proof of climate-driven collapse; after it, the text lays out Okonkwo's reasons (decadal resolution, regional averaging, local variables) for saying her data show only that conditions changed. 'More circumspect' explicitly contrasts her caution with their haste, so the sentence's job is to introduce that contrast. (B) mistakes 'circumspect' for an admission of methodological inferiority; the text never compares Okonkwo's precision with the historians' — the historians are cited as interpreters of her data, not as producers of rival measurements. (C) misidentifies the parties: the tension is between a scientist and historians, not among geochemists, and it concerns what an inference can support, not how cores are dated. (D) misreads who made the collapse claim: the historians drew that conclusion from her data, so Okonkwo has nothing to revise — she is restraining others' inference, not retracting her own.

Why the other answers are wrong

B. It concedes that Okonkwo's dating methods are less precise than those relied on by the historians who cite her work.
"Circumspect" here means cautious about what her data can prove, not an admission of imprecision; the historians interpret her data rather than producing rival measurements to compare against.
C. It introduces a dispute among geochemists about how sediment cores from crater lakes should be interpreted.
The tension is between Okonkwo and the historians citing her, not among geochemists, and it concerns what her data can support rather than how cores should be interpreted.
D. It indicates that Okonkwo has revised the conclusions she originally drew from her sediment cores.
The climate-collapse conclusion was drawn by the historians, not by Okonkwo, so she has nothing to retract—she is restraining their inference.

More Craft and Structure questions

Not affiliated with the College Board. SAT is a trademark of the College Board.