Question

since when did people move away from desert
the discovery of oil
the disovery of soil
the discovery of plants
the discovery of fire

Explanation:

To determine when people moved away from deserts, we analyze the options. Oil discovery in desert regions (like the Middle East) led to economic opportunities and infrastructure elsewhere, prompting migration. Soil, plants, or fire discoveries don't relate to large - scale desert migration as oil did.

Answer:

A. The discovery of Oil