Which one of the following best describes the organization of the last paragraph? A. Several alternative answers are presented to a question posed in the previous paragraph, and the last is adopted as the most plausible. B. A question regarding the cause of the phenomenon described in the previous paragraph is posed, two possible explanations are rejected, and evidence is provided in support of a third. C. A question regarding the phenomenon described in the previous paragraph is posed, and several incompatible views are presented. D. A question regarding the cause of the phenomenon described in the previous paragraph is posed, and several contributing factors are then discussed. E. Several answers to a question are evaluated in light of recent discoveries cited earlier in the passage.