Describe the last group of boys to arrive at the meeting\

B

Explanation:

It would not be D because D is the location of a common ancestor, AKA an animal that does not haver jaws or bones. It would not be C because the question states that the fish has jaws, and C does not have jaws since the arrow does not point to that. It would not be A because the question states the fish has "NO TRUE BONES", meaning that there are no bones present. And in A, there is the bones arrow pointing to it, meaning that A has bones since that trait is on the same horizontal line as A. Only leaving us with option B left, since it came from an ancestor with jaws but not from an ancestor with bones. Sorry, I'm not the best with explaining but hopefully that makes sense why it is B, it's like a family tree, you just have to follow it carefully :) I hope that helps