What is the purpose of putting the following sentence in the letter? We know you'll do the right thing by letting the trees continue to beautify and shade our school. A. It is an example of propaganda that gives the principal wrong information about the trees. B. It is a form of persuasion that helps the principal understand the facts about the trees. C. It supports the author's concern that the principal is not a very intelligent person. D. It is a form of persuasion that suggests the principal is smart enough to "do the right thing."

B. It is a form of persuasion that helps the principal understand the facts about the trees.