...................... began when humans started using metals instead of stone.APalaeolithic AgeBMesolithic AgeCThe Metal AgeDThe Neolithic AgeAnswer: C. The Metal Age Read Explanation: METAL AGE'The Metal Age' began when humans started using metals instead of stone.This age clearly reflects the human progress in technology.Copper was the first metal used by humansThe presence of copper was found in the early agrarian villages of Catal Huyuk (Turkey), Cayonu (northern Syria) and Ali Kosh (Iran).It is believed to have existed around 7000 BCE. Read more in App