Which of these technologies helps to improve employee efficiency?

A. They were forced to remain in one place at all times.

This is false, for if they remain in this one place at all times, then the animals would eat off all the grass and other food, and then they would slowly die off because there is no food left.

These are true because:
B: Because they move around, you really only carry what you need, and unlike cities with storehouses and such, you really only carry what you can carry on your back
C: they are nomad pastorals which meant that they have herds of animals to both feed them and give them clothing and such. As they move around they don't have time to plant crops.
D: As you move around, you will encounter some places with harsh climates and limited water supplies. As long as it can sustain the herd (as water is always limited) they can stay there until they need to find a larger area with more food and supplies.

hope this helps :D