Answer:
B. It lends credibility to your paper.
Step-by-step explanation:
A persuasive essay (also called an argumentative essay) is a type of essay written to convince readers to believe in an idea or opinion and perform an action. When writing a persuasive essay, you should use logic and reason to prove that your point of view is the correct one. Your arguments should be supported by convincing facts.
Besides that, it's very important to pay attention to the conventions of the language you are writing your essay in. We are more likely to believe someone who uses correct grammar than someone who makes mistakes. That is how proper language lends credibility to your paper.