This question asks you to identify the primary focus of the passage. The best answer is B. The author describes the new theoretical model in the first paragraph; in the final paragraph the author states that the data obtained from actual observations, which are discussed in the second and third paragraphs, is consistent with the new theoretical model. Choice A is not correct; the computer model confirmed the astronomers’ hypothesis that meteor streams broaden with time, and although the model yielded an unexpected result, the passage does not contrast the predictions yielded by competing theories. Choice C and D are not correct because the passage makes no reference to further areas for research, and only a single phenomenon is described in the passage.