Under Khrushchev, how did the USSR proceed in the arms race with the US?

The USSR under Khrushchev competed with the United States by advancing its military technology and developing powerful new weapons, including nuclear weapons and missiles. This matches choice C, “They developed new and powerful weapons.” The question is about building up capabilities in the arms race, not using weapons to invade countries or suppress dissenters.

AI-written and checked against the verified answer.