The correct answer is D. Extempore.
An extempore speech is a speech that is delivered without previous preparation. It is a type of impromptu speech, which is a speech that is delivered on the spot without any preparation. Extempore speeches are often used in business settings, such as when a CEO is giving a presentation to shareholders, or in political settings, such as when a candidate is giving a campaign speech.
Extempore speeches can be difficult to deliver, as they require the speaker to think on their feet and to be able to articulate their thoughts clearly and concisely. However, extempore speeches can also be very effective, as they allow the speaker to connect with their audience in a more personal way.
A prologue is a speech that is delivered at the beginning of a play or other performance. It is typically used to introduce the characters and the plot of the story. A soliloquy is a speech that is delivered by a character alone on stage. It is often used to reveal the character’s thoughts and feelings.
Neither a prologue nor a soliloquy is delivered without previous preparation. A prologue is typically written by the playwright, and a soliloquy is typically written by the actor who delivers it.