Which type of lecture aims to persuade, inform, or entertain?

The correct answer is the type of lecture that is designed primarily to persuade, inform, or entertain, which aligns with the characteristics of a formal speech. A formal speech often includes structured presentation elements and seeks to engage the audience through various rhetorical techniques while addressing a specific topic or purpose. This category of lecture typically aims at delivering a message that resonates with the audience emotionally or intellectually, often utilizing storytelling and persuasive language to achieve its goals.

Other options may focus more specifically on distinct purposes, such as teaching or providing information in a concise manner. For example, a teaching lecture primarily aims to educate students on a particular subject without necessarily seeking to entertain or persuade. Similarly, a briefing is usually a short presentation that conveys critical information quickly and directly, often in a business or military context, while an illustrated talk combines visuals with spoken content but may not have the same depth of persuasive intention as a formal speech.