This stimulus identifies a specific problem: there is no satisfactory long-term storage for radioactive waste plants. One solution to this problem is identified: people should shut down all present nuclear plants, and build no new nuclear plants. This proposal would, if adopted, prevent the creation of any new radioactive nuclear waste. However, this proposal does not address what ought to be done with all the existing radioactive waste that has already accumulated. Thus, the proposal falls short of offering a complete solution to the problem identified. Answer choice (C) is correct, because it identifies this limitation--the proposed solution "does not provide for the permanent storage of already-existing waste."
Both (A) and (D) can be eliminated because the stimulus is not about the problem of safe alternative technologies for producing electric power. (B) can be eliminated because the stimulus is not about safe operation reputation--it's not about how a nuclear plant operates. It's about what is done with radioactive waste produced by the nuclear plant. And (E) can be eliminated because it is not an accurate description of the stimulus. The stimulus makes clear that the risks of unsafe disposal of radioactive waste is a PRESENT problem, not just one that lies in the future. And (E) does not describe the limitations of the solution offered in the stimulus.
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