A thesis statement focuses your ideas into one or two sentences. It should present the topic of your paper and also make a comment about your position in relation to the topic. Your thesis statement should tell your reader what the paper is about and also help guide your writing and keep your argument focused.
What would happen to writing if paragraphs didn't exist is that when the reader reads the writing, he/she might skip a sentence or even get confused. And then you might not understand it yourself. It can affect the reader by not understanding what is going on in the writing if it's a story.
Answer:
A, "it is usually easier to trust him or her in return"