What was the main purpose of Truman's speech

a)to frighten the soviet gobernment
b)to make clear how the United States would respond to Communist aggression c) to win congressional approval of the containment policy d)to expand the cold war

a is silly with the word "frighten"

b the policy was to me unclear, it just said we would support...
c. Robert Taft was a leader in the Senate, and he was a blue blooded Isolationist, Trumans speech put pressure on him.
d. this started the cold war, not expanded it.

So C is correct..?

The main purpose of Truman's speech, known as the Truman Doctrine, was to make clear how the United States would respond to Communist aggression. To confirm the answer, you can refer to primary sources such as transcripts or recordings of Truman's speech. These are widely available online or in historical archives. By reviewing the speech, you can understand the context and objectives behind it, allowing you to confidently select the correct option, which is b) to make clear how the United States would respond to Communist aggression.