Answer:
(C) to warn America and the world about the threat that the Soviet Union and the rise of communism posed to freedom and peace
Explanation:
Churchill gave a very descriptive phrase that shocked the United States and Britain, "From Stettin in the Baltic to Trieste on the Adriatic Sea, the iron curtain descends on the European Continent."
Before this speech, the US and Britain were concerned about their postwar economy and remained very grateful for the proactive role of the Soviet Union in ending World War II. That was Churchill's speech, which he gave the title "The Sinews of Peace," which changed the way the democratic West viewed the Communist East.