The Integrated Services Digital Network (ISDN) sends telephone transmissions across what type of lines?

The correct answer to the following question will be "Digital".

Explanation:

A digital line seems to be a type of line of communication that requires only binary code for transmission and release.

ISDN (Integrated Services Digital Network) is a wireless enterprise-only connection that links a conventional phone system to the telephone line, enhancing the visibility and efficiency of communications. It is indeed a series of connectivity protocols across the conventional networks of the community activated mobile phone network enabling seamless wireless delivery of audio, display, content, and other related services.