Which of the following reports focused on fire protection in the United States and was published in 1973?

The report that focused on fire protection in the United States and was published in 1973 is "U.S. America Burning." This report, commissioned by the National Commission on Fire Prevention and Control, highlighted the critical state of fire safety and the increasing incidence of fire-related incidents across the country. It aimed to address the numerous issues surrounding fire prevention, life safety, and emergency response, ultimately leading to recommendations for better fire safety practices and policy improvements.

The other options, while they concern fire safety, either describe reports published at different times or pertain to contemporary discussions and revisits of the topic rather than the original 1973 report. This emphasizes the significant role “U.S. America Burning” played in shaping fire prevention policies and awareness during that era.