The question whether intelligent life exists elsewhere in the universe is certainly imprecise, because we are not sure how different from use something might be and still count as "intelligent life" Yet we cannot just decide to define "intelligent life" in some more precise way since it is likely that we will find and recognize intelligent life elsewhere in the universe only if we leave our definitions open to new, unimagined possibilities.
The passage, if seen as an objection to an antecedent claim, challenges that claim by:
(A) showing the claim to be irrelevant to the issue at hand
(B) citing examples that fail to fit proposed definition of "intelligent life"
(C) claiming that "intelligent life" cannot be adequately defined.
(D) arguing that the claim, if acted on, would be counterproductive
(E) maintaining that the claim is not supported by the available evidence.
A 750 aspirant.