How do historians learn about people who live in the earliest historical eras?

From old historical objects

“the iliad” (gr: “iliás”) is an epic poem by the ancient greek poet homer, which recounts some of the significant events of the final weeks of the trojan war and the greek siege of the city of troy (which was also known as ilion, ilios or ilium in ancient times).

i don't think it's c or d. i think it's either a or b.

hope this .