Correct Response: C. If hospitals are to adopt the alternative therapy to reduce post-surgical pain, the most useful method to assess the usefulness of this treatment would be to know whether the alternative therapy is at least as effective as more traditional methods of pain reduction. Having information about the percentage of patients reporting reduced pain after receiving other forms of treatment would allow this assessment to be made. Information about the percentage of patients in all hospitals who experienced severe pain after surgery (A), the cost of the alternative therapy (B), and the level of pain reported pre-and post-alternative therapy (D) would not be helpful in determining if the alternative therapy was as effective in reducing pain as other treatment methods and, therefore, whether the therapy should be used in all hospitals.