Question

the apollo-soyuz test project was an example of
the race for supremacy in space.
cooperation in the development of space technology.
the cold war at its height.
fading interest in space exploration.

Explanation:

The Apollo-Soyuz Test Project was a joint 1975 mission between the U.S. (Apollo program) and the Soviet Union (Soyuz program), marking direct collaboration in human spaceflight during the later Cold War, not competition, peak Cold War tension, or declining space interest.

Answer:

cooperation in the development of space technology.