The Roman Empire conquered many countries in three different continents. The continent of Europe included parts of Gaul, (Modern day France, and surrounding countries.) Spain, Britain, The Italian Peninsula, and Greece/Macedonia. In Asia and Africa the Roman Empire conquered parts of The Holy Land, Egypt, and Carthage.
Your answer is the first one. Domestic Servant, Skilled Trades, and field workers.
Historians must look at the age of the evidence itself, they must also look at whether it can be corroborated by other pieces of historical evidence and that the source of the evidence is reliable.