The correct option is B Passage 1 presents an argument, while Passage 2 surveys current opinion in a debate.
Where passage 1 presents an argument about the existence (or not) of extraterrestrial civilizations (and if they exist, where are they?), passage 2 talks about current views and opinions on the same debate: if there are extraterrestrials, where are they? Why haven't they visited us already? In this context, option B best illustrates a significant difference between both the passages.