The correct answer is C) ancient.
The meaning of "paleo" is ancient.
Historian and scientist use this term to refer to the ancient times were the first humans lived. For instance, archeologists say that in this "paleo" ancient times, humans stopped to be nomads, started to learn agriculture techniques and use basic tools for basic necessities. First, they used stone tools, rocks, and later they were able to use bronze tools in the Bronze Age.