A _________ speech is pre-planned with an outline but not written out.

An extemporaneous speech is characterized by being planned and structured with a clear outline, but it is delivered without a script. This allows the speaker to maintain a natural flow and engage with the audience while covering the main points of their outline. This type of speech often combines spontaneity and preparation, making it effective for delivering content in a conversational manner.

In contrast, an impromptu speech is delivered without preparation and is generally more spontaneous. A manuscript speech involves reading directly from a written script, which restricts the speaker's ability to connect with the audience dynamically. Expository speeches are designed to explain or inform about a specific topic, but they can take various forms that do not necessarily align with the idea of being pre-planned yet unwritten. Thus, the nature of an extemporaneous speech makes it the correct choice in this context.