Answer:
A. Metal tools
Step-by-step explanation:
The Neolithic Era was the last phase of the Stone Age. It was characterized by the invention of agriculture which led human communities to become sedentary and to form agrarian empires. The term Neolithic derives from the Greek for "New Stone", in opposition to the "Paleolithic" which means "Old Stone", referring to the new technologies of polishing stones developed by several communities around the world between 12000 and 7000 years ago. This era ended with the development of metal tools, which started with the Copper Age around 5000 BCE and was followed by the Bronze and Iron Ages. For this reason, metal tools were not developed during the Neolithic Era because this technology was developed much later.