B probably, I’m sure that’s the most weak one.
In the aftermath of World War II, America became the leader of the world, and Britain's Empire had suffered greatly. This led voters to become uncomfortable with their respective country's new role in the would, which cause political change.
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George Washington believed the cause of Shays' Rebellion was the weakness of the central government to keep such instability from spreading
Your perspective can influence the speech because of your experiences.
Say that you had an experience on the topic, and you now have background evidence to support your side. The other side will contradict you but they may not know what it feels like to be in the experience of the topic.
Therefore, your perspective can make your speech biased, or it can be proved with evidence. This is all caused by your perspective on the topic.