A、The Times. B、The Observer. C、The Guardian. D、Financial Times. B原文中提到，The Observer于1791年开始每周日发行，这使得该报成为世界上年代最久远的国家性报纸，故答案为B。

Today I’d like to talk about the newspapers in the United Kingdom. The United Kingdom has one of the world’s oldest established newspaper industries. In the late 18th and early 19th century, as the British economy began to industrialize and literacy levels rose through the introduction of mass education, more and more newspapers began to appear. The Times, which first appeared in 1785, is the United Kingdom’s oldest daily newspaper. While The Observer, which is still published every Sunday, began publishing in 1791, making it the world’s oldest national newspaper.
    The different main British newspapers—The Times, The Observer, The Guardian, Financial Times—still suggest that the function of a paper is to offer objective reports about what is happening in the country. The function of supervising the government is one of the reasons why a free press is considered so important to the functioning of parliamentary democracy. Besides, politicians and businessmen paid more attention to the power of the press. They used press to push their products and services to potential customers, so the advertising business was born. In Britain, most advertising is carried in newspapers; companies use the press to sell products; people use the press to look for a job, or to buy a house. All the British media must follow Advertising Codes which ensure that advertisements are legal, honest and truthful, have a sense of responsibility for consumers and society and respect the principles of fair competition.
    British newspaper culture is unusual in the extent to which class and educational differences are reflected in the newspapers people read. In other developed countries like Japan and the United States, newspaper reading is a habit of mainly middle classes, however, in Britain the "lower classes" are also regular readers. There are more than 1500 different newspapers which cater for a wide range from political to educational views. Britain has one of the highest levels of newspaper sales per head of population in the world. Although most newspapers are financially independent of political parties, they also express some political views.
    Questions 16 to 18 are based on the recording you have just heard.
    16. Which of the following is the world’s oldest national newspaper?
    17. What is the major function of a newspaper?
    18. What do we know about the newspaper reading in Britain?