All situations involving communication involve at least one of the following:

• an author with specific purposes, attitudes, and background
• ?
• a text in a particular medium, made with certain tools, and deciphered with certain tools
• a context in a particular time and place involving a certain community and conversation

one of the characteristics from the list above is missing. which of the following phrases correctly completes the list?
a.
a web master with a specific agenda
b.
an audience with equally specific purposes, attitudes, and background
c.
a power point presentation created by the writer, having a clear introduction and conclusion
d.
a meeting in a particular building involving members with specific purposes, attitudes, and backgrounds