This question asks you to identify the "primary purpose of the second paragraph." When you get a question like this where it points you to a specific part of the passage, it's best to begin by re-reading the specific part at issue.
Then, turning to the answer choices:
(A) is incorrect because the second paragraph does not build on the first paragraph. The first paragraph provides an explanation of dowsing. But, the tone shifts with the second paragraph as the author describes the views of "those skeptical of dowsing."
(B) is incorrect because the paragraph doesn't offer two perspectives. Rather, it describes one perspective, that of those who are "skeptical of dowsing."
(C) is correct because the second paragraph presents the arguments of those "skeptical of dowsing" and then the third paragraph presents the arguments of "proponents of dowsing." The third paragraph thus contains counter-arguments to the arguments raised in the second paragraph.
(D) is incorrect because the paragraph does not explore a claim which was raised in the first paragraph. The first paragraph simply explained dowsing. The second paragraph then explains the arguments of those skeptical of dowsing. These skeptics were not mentioned in the first paragraph.
(E) is incorrect because it mixes up when the arguments are being presented. The entirety of the second paragraph deals with the arguments of the skeptics. Then, the entirety of the third paragraph deals with the arguments of the proponents. Then, finally, the fourth paragraph tries to resolve the arguments. This answer choice says that both sides are discussed in the second paragraph, when that is not the case.
