Why did the Einstein-Szilard letter warn President Roosevelt about in 1939?

That the US was secretly researching nuclear weapons

that Germany was researching nuclear weapons

That the US planned to use nuclear weapons against Japan

That Germany planned to use nuclear weapons against Japan

In 1939, the Einstein-Szilard warned President Roosevelt that Germany was researching nuclear weapons.

Explanation:

The Einstein-Szilard letter was sent to President Franklin Delano Roosevelt in August 1939. It warned Roosevelt that Nazi Germany could be conducting research on the possibility of using nuclear fission to create atomic bombs, and suggested that the United States should also begin to conduct research in this regard themselves.

That Germany was researching nuclear weapons.