First metal to be found?

copper

Explanation:

Copper was first used by man over 10,000 years ago. A copper pendant discovered in what is now northern Iraq has been dated about 8700 B.C. For nearly five millennia copper was the only metal known to man, and thus had all the metal applications.

The first discovery of metal probably happens during the period of 4000 BC. And the first metal that was used by man was copper and gold.

Explanation:

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the enslavement and death of yeet

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

explanation: