Answer:
C.
They promoted the idea of a free market, which helped strengthen the global economy.
Explanation:
Smith's ideas of free trade opposed Mercantilism and protected markets. He believed that nations were better off when goods were exchanged freely and every country tried to specialize in the goods they were better endowed to produce. His ideas followed a certain Newtonian understanding of the world, and he believed that there was an underlying force that regulated the economy naturally.