25 !
which of the following made it possible for the united states and the soviet union to develop intercontinental ballistic missiles (icbms) equipped with nuclear weapons?

a. the start of the space race
b. development of the hydrogen bomb
c. the invention of high-efficiency jet fuel
d. improvements in rocket-propulsion systems

Development of the Hydrogen bomb.

Explanation:

Intercontinental ballistic missiles are long-range guided ballistic missiles with a minimum range of thousands of kilometers this missile use ballistic trajectory.

During the cold war era, the United States and soviet union both started research programs on the development of the ICBMs, in the united states different private defense research companies are working on the development of the ICBMs while in the Soviet Union the program of developing ICBMs was centrally organized.