Considering the situation described above, Arianna is required to file a Schedule B if her dividend income is higher than "$1,500."
According to the existing rules and regulations, individuals must file a Schedule B when the total amount of dividends or interest received is over $1,500.
Generally, it should be noted that Schedule B only requires individuals to report information about the received dividend and interest income.
Hence, in this case, it is concluded that the correct answer is "$1,500."
Learn more about Schedule B here: https://brainly.com/question/25116167