D, 19th century refers to 1800 and 20th to 1900 but it doesn’t include/contrast past music, so wrong. C doesn’t help you with past music. B could be of use, but the report is about 1920 big band music and not hip hop. And A would allow you to have the best information from a first person source along with their contracting ideas with today’s and the pasts music, so A is the right answer.