The best explanation of the effect of South Carolina’s physical geography and climate on its role in mercantilism is:
South Carolina’s physical geography and climate produced cash crops such as indigo, rice, and tobacco to trade as raw materials.
This response accurately highlights how the state's agricultural conditions supported the cultivation of these cash crops, which were essential for trade within the mercantilist system. The warm climate and fertile land in South Carolina were ideal for growing these products, making it a valuable contributor to the colonial economy and trade networks.