【題組】49. How are the paragraphs in the passage related to each other?
(A) The first paragraph presents a problem, and the second and third paragraphs provide details on how to solvethe problem.
(B) The first and second paragraphs introduce two different arguments on an issue, and the third gives theconclusion.
(C) The third paragraph provides a summary of the two problems discussed in the previous two paragraphs.
(D) The first paragraph introduces an argument, and the second and third paragraphs provide supporting evidencefor each side of the argument.