Odd one out: Telephone

Explanation:
The odd one out in this group is the telephone.

Reasoning:
- Radio, television, and newspaper are all forms of communication media that provide information to the public.
- Radio: Radio is a device that allows for the transmission and reception of radio waves, which are used to broadcast audio content such as music, news, and talk shows. It is a common form of entertainment and information dissemination.
- Television: Television is a device that allows for the transmission and reception of visual and audio content. It provides a wide range of entertainment, news, and educational programs to the viewers.
- Newspaper: Newspaper is a printed publication that contains news, articles, advertisements, and other information. It is a traditional form of media that provides detailed and in-depth coverage of various topics.

However, telephone is different from the other options because:
- Telephone: Telephone is a device used for voice communication between two or more people over a distance. It allows for real-time conversation between individuals. Unlike the other options, the telephone is primarily used for personal communication rather than broadcasting information to the public.

Conclusion:
Therefore, the odd one out in this group is the telephone because it is a device for personal communication, while the other options are media forms used for broadcasting information to the public.

Newspaper, Radio and Television are the sources of Mass communication and Telephone is the service of Telecommunication.