GMAT Critical Reasoning (CR) | Re: As a practical matter, the copper available for industrial

Look at the conclusion

Copper can be made from other materials.

Now you need to find a reasoning that helps you to say: that's not true. The only way to weaken the argument is choice B. To make copper from other material is an expensive process.

E is wrong because talks about the estimation of the amount of copper and how it is become sophisticated. But E does not help to weaken out conclusion. E is far apart from out primary scope

Hope this helps

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