What is the main cause of the shift between neolithic and paleolithic age?

The main cause of shift from Paleolithic(Old Stone Age)to the Neolithic Age(New Stone Age) is that the temperatures were getting warmer, so now this shift was a great impact on the population.. Now people were able to be sedentary because of the warmer climates and make new civizilations, laws, and government structures.

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Vixinus

It's either a or d. i'm pretty sure it's d though as rome fell in 476 c.e