To what extent did Greek poleis control trade? Group of answer choices trade was largely free and carried out by independent merchants, but some control was exercised over the grain trade to ensure accessibility Greek poleis organized trading expeditions for major resources such as grain, metal, and stone trade was carried out by independent merchants, but the poleis negotiated agreements with other cities which determined where their merchants were able to trade trade was carried out by independent merchants, but the poleis set prices in their markets for most commodities