Answer is B
People live near oasis, which is a source of water. Nomads are able to quickly pack their belongings to move from one place to another to find food. Food supplies can run out in an area because of lack of farming. Modern technology such as lightweight plastic and metal containers and even satellite phones help make life easier in the desert now.
Drilling machines cut through rock to find underground water. Also, trucks and planes improved desert transportation.
It's easier to get around the desert now!
