Answer:
I believe it is
fur color that closely matches the eucalyptus bark color
or B
Step-by-step explanation:
My reasoning is that, if they evolved from land-dwellers to tree-dwellers, they will have almost no need for longer legs for running, as they only need strong legs and arms for climbing, not running.
The ability to communicate better doesn't really mean anything, as they are now all closer or further away, since they are all in trees now. This doesn't mean that they necessarily need to communicate better.
The ability to have several offspring at one time could be the answer, but isn't really necessary.
Predators would hunt for the koalas in the trees now, so to hide, they would need to go inside the tree trunk or camouflage themselves, which most creatures do by blending into their surroundings or changing skin color over time.
I got this question on Edge 2021 biology finals so...