The correct answer is the following.
The Neolithic Revolution.
The event that led to the others was the planting a seed
The Neolithic Revolution is also known as the Agriculture Revolution. It was the time in human history when humans stopped being Nomads and started to settle in one place to establish the firsts civilizations, as was the case of the Sumerians, the oldest civilization on Earth. The Sumerians settled in the middle of the Euphrates and Tigris Rivers, in the Middle East.
They developed agriculture techniques, learned to benefit from the flood of the rivers to have fertile soil and grow crops, planted seeds, domesticated animals, produce a surplus of food, and established powerful city-states such as Nippur, Eridu, Lagash, Kish, Uruk, and Ur.