单选题

　　[完成句子]Amongst the most popular books being written today are those which are usually classified as science fiction. Hundreds of titles are published every year and are read by all kinds of people. Furthermore， some of the most successful films of recent years have been based on science fiction stories.

　　People enjoy___________.

　　A、a recurrent theme

　　B、reading books of science fiction

　　C、read worldwide

　　D、political implications