After the soviet union launched sputnik i in 1957, the united states responded by
a) blockading east berlin.
b) buying their rocket technology.
c) attempting to shoot it down with missiles.
d) increasing funding to its own space program.

D) increasing funding to its own space program.

Explanation:

Sputnik-1 was the first artificial satellite launched worldwide. This satellite was built with Russian technology and placed Russia as a possible technological power, making communism advance in the ideological battles that underpinned the cold war.

With this event, the USA realized that they also needed to invest in space technology and establish their name as a technological power better and bigger than Russia, for this reason, after the launch of Sputnik-1, the American government decided to increase the financing for its space program itself.