What 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

That Germany was researching nuclear weapons.

Explanation:

This letter was written by Leo Szilárd and signed by Albert Einstein, and sent to warn the President of US Franklin D. Rooselvelt in 1932, about Germany developing atomic bombs.

i think they would live in caves or natural tunnels

either b) they were often feared and despised by other native cultures. or

c) their obsession allowed them to coexist with many other native cultures because of their peaceful nature.