The correct answer is: a) Copper along with stone tools.
The Chalcolithic period, also known as the Copper Age, was a period of human development that began around 5,000 BC and ended around 3,000 BC. During this time, humans began to use copper tools and weapons, along with stone tools. Copper is a relatively soft metal, so it was often used in combination with stone to create tools that were both strong and durable. The Chalcolithic period was a time of great innovation and
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