Of course, all of these are predictions. Scientists have said it’s almost impossible to truly predict how evolution will unfold. As we go further and further out, the prediction is less accurate. And it’s even more difficult to predict whether another species will develop human-level intelligence, Some think that it could happen. Others, however, are less optimistic because they don’t think nature will make mistakes twice.

Which of the following best describes the future of other species filling the same role as humans?

A．Hopeless.	B．Challenging.
C．Promising.	D．Uncertain.