Answer:
The sentence that best summarizes Truman's persuasive strategy in this part of the speech is Truman triggers fear in the audience by suggesting freedom could be lost.
Step-by-step explanation:
In this speech Harry S. Truman point out the idea that a threat should be ended as it starts in order to avoid any kind of uncertainty to the country safety, he also makes a call to other countries to join his fight as this threat could reach all if it becomes big and powerful enough in case they keep on being still in the matter.