Final answer:
(2) Karl Marx is the most influential figure in fostering modern socialism, having analyzed historical class struggles and proposed a proletariat revolution leading to socialism and communism. Adam Smith, John Locke, and Friedrich Hayek, on the other hand, are associated with economic liberalism and the advocacy of free markets.
Step-by-step explanation:
When considering who has tended to foster modern socialism, the most influential figure is undoubtedly Karl Marx. Marx's work, often associated with his collaborator Friedrich Engels, critically analyzed historical class struggles and laid the groundwork for modern socialist thought. They envisioned socialism emerging from a working-class revolution against capitalist owners, overthrowing the existing system to seize the means of production, and moving towards a socialist and eventually communist state.
In stark contrast, Adam Smith was a foundational figure in economic liberalism and is best known for articulating the principle of laissez-faire, which calls for minimal government intervention in economic affairs. John Locke and Friedrich Hayek are also associated with this economic liberalism, advocating for individual rights and free markets, with Hayek specifically attacking socialist models in his works.