2) What did the leader of the Soviet Union, Nikita Krushchev, secretly do to assist Cuba?

he gave them nuclear bombs

Explanation:

Nikita Khrushchev  (1894-1971) led the Soviet  Union during the height of the Cold War, serving  as premier from 1958 to 1964.  Though he largely pursued a policy of peaceful coexistence  with the West, the Cuban Missile Crisis began after he positioned nuclear  weapons 90 miles from Florida.

its c not d   tell me if that´s correct

that would be the steamboat because none of the other things are forms of transportation