This supports Dr. Pagano's argument. If checkerspot butterflies are very sensitive to temperature changes, then it seems likely that a shift in global climate would also cause a shift in the butterfly population distribution.

This supports Dr. Pagano's argument. Even though the the butterflies aren’t directly affected by climate, they are affected indirectly by climate's effects on their food sources, which grow better in warmer climates. This helps explain why they’ve expanded their range north as global warm zones shift northward.

This wouldn't support Dr. Pagano's argument. If the butterflies can adapt to many climates, then it seems less likely that the reason for the change in their population distribution is climate change.

This supports Dr. Pagano's argument. If the butterflies don't thrive in lower temperatures, it makes sense that they would move north toward warmer zones.

This supports Dr. Pagano's argument. If closely related butterflies survive only in warm climates, then it seems more likely that checkerspot butterflies would also require warm climates to thrive, which would explain their northward movement.