What did we invent and not join in World War II

Explanation:

Technology played a significant role in World War II. Some of the technologies used during the war were developed during the interwar years of the 1920s and 1930s, much was developed in response to needs and lessons learned during the war, while others were beginning to be developed as the war ended. Many wars had major effects on the technologies that we use in our daily lives. However, compared to previous wars, World War II had the greatest effect on the technology and devices that are used today. Technology also played a greater role in the conduct of World War II than in any other war in history, and had a critical role in its final outcome.

d) a constitutional amendment

sorry i really dont know