Which of the following statements is true of the Sahara Desert, the Arctic and sub-Arctic regions of North America?

A.

The areas inhabited by primitive hunters and traders

B.

These areas have the world's largest known deposits of crude oil

C.

population is found in isolated oases and along the river valley's

D.

The enviroment is very harsh for both man and animal

E.

The inhabitants belong to the oldest races in the world

Correct answer is D

No explanation has been provided for this answer.