Which event marked the start of the nuclear arms race?

Soviet Union's first test of an atomic bomb in 1949

United States' first test of a hydrogen bomb in 1952

Soviet Union's launching of Sputnik 1 in 1957

Cuban Missile Crisis of 1962

Question

Which event marked the start of the nuclear arms race?

 Soviet Union's first test of an atomic bomb in 1949

 United States' first test of a hydrogen bomb in 1952

 Soviet Union's launching of Sputnik 1 in 1957

 Cuban Missile Crisis of 1962

anonymous · Answer

United States' first test of a hydrogen bomb in 1952, i think

anonymous · Answer

Thank you! I tried it.
What about :
Which of these statements explains why Sputnik disturbed Americans?

 It led other countries to admire communism.

 The satellite was capable of launching a nuclear bomb.

 It was infuriating that the Soviets had launched a dog into space.

 It showed that the Soviets could develop a missile capable of hitting the U.S.

anonymous · Answer

try D, i am not too sure on this one

anonymous · Answer

First was wrong, second was right. Thank you:)

anonymous · Answer

you are welcome, and if you need anymore help, let me know