Final answer:
Shifts in American public opinion about the Panama Canal reflect changes in perspectives on global trade, infrastructure projects, and international diplomacy. The canal is a symbol of U.S. expansion and influence in global commerce and changes in its perception align with broader foreign policy and globalization trends.
Step-by-step explanation:
Shifts in American public opinion of the Panama Canal indicate d) All of the above: Changing perspectives on global trade, shifting attitudes towards infrastructure projects, and evolving views on international diplomacy. The Canal has long been a symbol of the United States' efforts to spread influence and facilitate trade through major infrastructure development. Its importance is highlighted by its role in global commerce, serving as a vital transportation link between the Atlantic and Pacific Oceans. The evolution of opinions about the Canal reflects broader trends in U.S. foreign policy, which include keeping the country safe, securing access to foreign markets, and protecting human rights, as well as the changing dynamics of globalization that affects business and government activities worldwide.