The correct options are: A - C - F
Roman trade was the engine that led to the economy of the late Republic and early Empire. Fads and trends of historiography and popular culture have tended not to deal with the economic base of the empire in favor of the lingua franca that was Latin and the deeds of the legions. Both the language and the legions were supported by commerce, being at the same time part of its spine. The Romans were businessmen and the longevity of their empire was due to their trade.
Forum cuppedinis of ancient Rome was a market that offered general merchandise while at least four other major markets specialized in particular merchandise such as cattle, wine, fish and vegetables, and the Roman Forum attracted the bulk of the traffic . All the new cities, such as Timgad, were arranged according to an orthogonal plane that facilitated transportation and commerce. The cities were connected to each other by good roads. The navigable rivers were used extensively and some canals were dug but neither left archaeological remains as clear as the roads and therefore are often underestimated. Peace was an important mechanism for the expansion of trade. All the settlements, especially the smallest ones, could be located in economically rational places. Before and after the Empire, defensive positions on mountain tops were preferred for small settlements, as piracy made the coastal settlement particularly dangerous to all, except the largest cities of the empire.
The Romans used round-hulled sailboats. The continuous "police" protection of the Mediterranean for several centuries was one of the main factors in the success of Roman trade, since the Roman roads were built more for the feet or the hooves of the horses than for the wheels, and could not stand the commercial transportation of goods over long distances. The Roman ships used would have been easy prey for the pirates if not for the fleets of Libran galleys and triremes of the Roman army.
An abundant and fairly standard and stable currency, at least until about 200 d. C., did much to facilitate trade (Egypt had its own currency in this period and some provincial cities also issued their own coins).
