The correct answer is B. It explains why Arianna needs the principal to believe her.
Step-by-step explanation:
In a story, conflicts occur as the main character struggles against another character or element in the story such as nature or society. In the excerpt presented, the conflict between the main character Arianna and the principal develops through their dialogue because as they talk the principal is reluctant to help Arianna even when she tries to convince him.
This conflict can be seen in "Well, let’s get you through this first semester. Then we’ll evaluate how well you’re doing" because the principal denies promoting Arianna to Spanish 3, which is something Arianna needs for an exchange trip. Also, after this, Arianna tries to convince him by showing how much she needs this, which shows her effort for making the principal believe her. According to this, in the dialogue, the conflict develops because "It explains why Arianna needs the principal to believe her" and the way she struggles while trying to get a positive response from the principal.