The Interstate Bridge over the Apache River, built in the

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The Interstate Bridge over the Apache River, built in the 1950s, shows a substantial amount of rust: as much as 45% of its surface is coated in rust. Community activists have argued that the bridge presents a hazard: it is likely to collapse in places where it has rusted through. Professors of mechanical engineering at the local university did an extensive analysis of the bridge. These professors and their graduate students determined that 98% of the rust on the bridge exists on the surface only, and actually seals the underlying steel from the corrosive influence of the elements. The results of this academic study suggest that the bridge is safe for continued use.

In the argument given, the two portions in boldface play which of the following roles?

(A) The first is evidence in support of the conclusion; the second is that conclusion.
(B) The first is the main conclusion of the argument; the second provides evidence that calls this conclusion into question.
(C) The first is evidence taken to support one conclusion; the second provides evidence that calls this conclusion into question.
(D) The first is a position that the argument opposes; the second is the conclusion of the argument.
(E) The first is an interpretation of evidence; the second calls that evidence into question.


For a discussion of boldface structure GMAT CR questions, as well as the OA & explanation for this question, see:
https://magoosh.com/gmat/2013/gmat-criti ... questions/

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Source: — Critical Reasoning |

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by Nitin.811g » Mon Sep 16, 2013 7:17 pm
IMO, the OA should be D

Well the answers seemed pretty close to one another. The only catch was that the second boldface was definitely a conclusion. Now Only Option A and D support that D is a Conclusion. A is ruled out and hence the OA should be D