Which of the following are classified as broadcast media?

Broadcast media refers to platforms that transmit audio and visual content to a broad audience. Radio and television are the quintessential examples of broadcast media because they are designed to reach a large public audience simultaneously through electromagnetic waves. Radio broadcasts sound content, while television combines sound and visual images, allowing for a diverse range of programming and advertisements to be aired.

In contrast, other choices include formats that do not reach audiences in real-time or through a public broadcast system. Billboards and newspapers provide visual advertising but are categorized under out-of-home and print media, respectively. Direct mail and email are methods of communication typically aimed at specific individuals rather than the mass public, which places them in the realm of direct marketing. Podcasts and blogs are also typically accessed by individuals on demand, rather than through simultaneity to a large audience, which also differentiates them from traditional broadcast media. Therefore, radio and television stand out as the correct classification for broadcast media.