Which artifact would be most useful for a historian trying to determine the volume of trade between europe and china along the silk roads

“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).

ba geologist finds four sedimentary rock she determines that no geologic events have shifted the layers she labeles them a,b,c,dbfrom top to bottom