"If the forest continues to disappear at its present pace, the koala will approach extinction," said the biologist. "...

Hi, I am still a bit confused about the explanation of why/how do we make the correct answer to be inconsistent. I get we have to because of the question... but approaching it I am confused. How would we know it is inconsistent? For the correct answer B, is it because it did not match our original diagram for not D--- not KAE? So for future questions, the correct answer has to contradict in some way?