Answer:
B. Free trade
Step-by-step explanation:
Adam smiths economic policy advocated for free trade. In his argument, if everyone is given the freedom and go ahead to produce goods and also exchange them as they want, and if market is open to competition domestically and internationally, then there would be greater prosperity compared to when the market is under strict rules of the government.
He is the father of Laissez faire economics. Laissez faire means to leave alone.