Final answer:
The key element that led people to settle into an agricultural lifestyle was the development of more efficient tools and techniques for farming.
Step-by-step explanation:
The key element that led people to settle into an agricultural lifestyle was the development of more efficient tools and techniques for farming. Agriculture began with simple technologies, such as using pointed sticks to break up the soil. However, it took off when people harnessed animals to pull a more efficient tool, the plow.
With the use of the plow, one family could grow enough crops not only to feed themselves but also to feed others. This knowledge of having abundant food each year, as long as crops were tended to, led people to abandon the nomadic life of hunter-gatherers and settle down to farm.