Final answer:
Civilizations originated following the Agricultural Revolution, which marked a shift from a hunter-gatherer lifestyle to a sedentary agricultural one.
Step-by-step explanation:
The correct answer is A. Agricultural Revolution. Civilizations originated following the Agricultural Revolution, which occurred approximately 10,000 years ago. This revolution marked a shift from a hunter-gatherer lifestyle to a sedentary agricultural one, where people began to cultivate crops and domesticate animals. This allowed for the development of permanent settlements, surplus food production, and the division of labor, which are key characteristics of early civilizations.