Which period marked the first use of copper?

The correct answer is Option 3 -Chalcolithic

Chalcolithic marked the first use of copper. It started at 6,000 BCE.

Chalcolithic Period: The Chalcolithic period, also known as the Copper Stone Age, occurred from approximately 3,000 BCE to 500 BCE. During this period, copper began to be used alongside stone tools. Agricultural communities continued to thrive, and there was evidence of trade, craft specialization, and the emergence of early urban centres.