Explanation
Correct answer: B.
Choice B is the best answer. Siraj’s hypothesis is that the Chicxulub impactor was a long-period comet. But Artemieva points to the iridium found in the crater and in “geological layers that were deposited worldwide after the impact” as evidence that it was actually an asteroid, not a long-period comet.
Why the other choices are wrong
Choice A
Choice A is incorrect. We can’t infer that this is how Artemieva would respond to Siraj’s hypothesis. Text 2 never discusses whether Wild 2 is representative of long-period comets in general. Rather, Text 2 presents Artemieva’s argument that the Chicxulub impactor was an asteroid, not a long-term comet.
Choice C
Choice C is incorrect. We can’t infer that this is how Artemieva would respond to Siraj’s hypothesis. Siraj’s hypothesis doesn’t make this connection: rather, Siraj hypothesizes that the Chicxulub impactor was a long-term comet.
Choice D
Choice D is incorrect. We can’t infer that this is how Artemieva would respond to Siraj’s hypothesis. “Soil samples from sites distant from the Chicxulub crater” is too vague. Only soil samples from sites that are connected to the impact in some way are involved in either hypothesis.