Final answer:
William Jennings Bryan's main campaign strategy was Populism, aiming to appeal to the common people against the influence of economic elites. He emphasized issues like the silver standard, which aligned him with the interests of struggling farmers and the working class. The correct answer is B) Populism.
Step-by-step explanation:
Bryan's main campaign tactic as he sought to combat the influence of economic elites, often referred to as the 'Titans', was populism. In the 1896 presidential election, William Jennings Bryan faced off against William McKinley and used Populism to appeal to the common people, especially struggling farmers and workers who were suffering due to economic hardships.
Bryan campaigned heavily on issues like the silver standard and appealed to Populist sentiments such as anti-elitism and support for agrarian interests. However, his association with Populist views made him depictible as a radical threat to economic stability, which was capitalized on by his opponents.
In the context of the given options, Bryan did not use philanthropy or industrialization as his main campaign tactics; instead, he focused on the needs and aspirations of the common people. Furthermore, Bryan was not an isolationist; this term would describe a foreign policy stance that he did not primarily advocate.