Which agency is the main body for promoting and developing tourism in the United States?

The correct answer is the Tourism Industry Association (TIA), now known as the U.S. Travel Association. This agency plays a critical role in promoting and developing tourism within the United States by advocating for policies that support travel and tourism, conducting research to inform industry practices, and marketing the U.S. as a travel destination. Its efforts are aimed at increasing visitor spending and enhancing the overall economic impact of tourism on communities across the nation.

This association also collaborates with various stakeholders in the tourism sector, including government entities, private businesses, and non-profit organizations, to create a more favorable environment for tourism growth. TIA's initiatives help to raise awareness of the importance of tourism to the country's economy and its role in job creation and community development.

In contrast, the other agencies mentioned may focus on specific sectors or aspects of tourism but do not serve as the primary agency for overall tourism promotion and development in the U.S. Their roles, while important, do not encompass the broad range of responsibilities that TIA holds in driving national tourism strategy and advocacy.