Which of the following is an example of oral discourse?

An example of oral discourse encompasses communication that occurs through spoken language. A conversation between friends exemplifies this type of discourse as it involves real-time verbal exchange and interaction, showcasing the dynamics of dialogue. This informal setting typically employs everyday language and allows for immediate feedback and response between speakers, which is crucial to oral communication.

While options such as a written essay, a formal presentation, and a blog post involve conveying information, they do so primarily through written means. A formal presentation could include elements of oral discourse if spoken aloud, but it may also rely on visual aids and structured formats that do not align with the spontaneity of casual conversation. Hence, the informal nature and spontaneous interaction of a friend's conversation make it the best representative of oral discourse in this context.