Answer: B. an audience with equally specific purposes, attitudes, and background.
Step-by-step explanation: In order to communicate we need to know the elements that make communication possible, like, the author with a specific purpose, attitudes and background, a text, which is the medium we can use to send the message, the context that will give the meaning to the message, and of course the missing characteristic is an audience, which like the author, will have specific purposes, attitudes and background that will influence the communication process.