Without the specific diagram you're referring to, I can provide a general approach. In a typical phylogenetic diagram, organisms that are closer together on the tree share more recent common ancestors and therefore have more similar DNA.
However, if you want the correct response based on common biological knowledge:
Bears (which are warm-blooded) and salmon (which are cold-blooded) would not be the pair that shares the most similar DNA, as they belong to different classes of vertebrates.
Warm-blooded and cold-blooded animals encompass a wider variety and would not be directly comparable as closely related groups.
Turtles and frogs are both reptiles and amphibians, respectively, and are more distantly related than other groups, but they might be closer than bears and salmon (depending on what the tree shows).
Vertebrates and invertebrates are clearly distinct groups with significant differences in DNA.
If the diagram shows a relationship, and without seeing it, typically, you would expect the closest relatives to be found in categories like "turtles and frogs" since they are both part of the larger group of animals. However, in an actual phylogenetic analysis, one would rely on the specific diagram for an accurate response.
If you have the diagram, I would recommend looking for the group that shares a more recent common ancestor. If you need a more precise answer, please provide the details from the diagram!
