You are presented with the quiz "Avian species are less likely to end up extinct if they what?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "if all members of a species cannot produce offspring then that species will likely become extinct" and "avian species are less likely to become extinct if they are common across large ranges". 

So, what's the best answer to the question?


 

      produce offspring     