The correct answer is A) The development of agriculture.
The development of agriculture was followed by job specialization, then by social stratification, and finally by chiefdoms.
After the Neolithic Revolution or Agriculture Revolution, humans learned agriculture techniques that allowed them to settle in one place after many years of being nomads. For instance, the Sumerian civilization established and flourished between the Tigris and Euphrates Rivers in the Middle East region, or the Egyptian civilization established next to the Nile River in North Africa. Then, during the Bronze Age in Europe, Aegean Civilizations in what today is Greece and the Aegean Sea developed job specialization, then social stratification, and finally by chiefdoms that started to control the region.