Final answer:
David Ricardo and John Stuart Mill supported the key principles of Adam Smith’s economic ideas, which include a free market and minimal government intervention, making option (d) the correct answer.
Step-by-step explanation:
The men who supported Adam Smith's basic ideas, which laid the foundation for classical liberalism and the free market economy, were David Ricardo and John Stuart Mill. David Ricardo introduced the theory of comparative advantage and further built upon Smith's ideas on free trade and market economies. John Stuart Mill, an English philosopher and economist, was also a proponent of economic liberalism and was influenced by the works of Adam Smith. Ricardo and Mill supported the principles of a free market and minimal government intervention, which are core to Adam Smith's economic theory.
Therefore, the correct answer to the student's question is (d) David Ricardo and John Stuart Mill. Both economists shared Smith's enthusiasm for the free market and held views that were in line with his regarding the role of the government and the benefits of a laissez-faire approach to economics.