according to the cladogram, which characteristic was used to separate bony fish from amphibians? jaws…

Brief Explanations:

In a cladogram, each branch point represents a shared characteristic. Bony fish and amphibians are separated at the branch where the characteristic of "lungs" is introduced. Bony fish do not have lungs (they typically breathe through gills), while amphibians have lungs (in addition to other respiratory structures like skin in some cases). The other options: jaws are a more ancestral trait (shared by more groups earlier in the cladogram), cartilage is not relevant here as bony fish have a bony skeleton (not cartilage), and bony skeleton is a trait that both bony fish and amphibians share (as amphibians also have bony skeletons).

Answer:

lungs