The last answer because he was trying to start the "league of nations"
Active military intervention
I believe it's <span>B.Researchers everywhere began to collaborate and share data.
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If the speaker is using the pronoun "I," that means they must be telling the story in the first person. They appear in the story and tell it from their own point of view.
The answer to your question is B. However the troops were eventually withdrawn from Vietnam due to disagreements from the American people.