Correct Answer: Vanished

Solution : The most appropriate choice is the second option.

Extinct means no longer in existence, and vanished conveys a similar idea of something disappearing completely.

The meanings of the other options are as follows:

• Vibrant means full of energy and life.
• Active means engaging in physically active pursuits.
• Living means being alive.

Therefore, the correct sentence is, "The once-thriving species has now vanished from the face of the Earth."