A laconic response is one that is:

A laconic response is characterized by being brief and to the point, often conveying information concisely without any unnecessary elaboration. The term "laconic" derives from the Spartan region of Laconia in ancient Greece, where the inhabitants were known for their terse speech. This means that when someone provides a laconic response, it is straightforward and efficient, delivering the essential information without excessive detail or embellishment.

In contrast, the other characteristics described in the other choices do not align with the meaning of laconic. A detailed and verbose response involves excessive wording and complexity, whereas a pleasant and encouraging response would focus more on tone rather than brevity. Lastly, being full of unnecessary information suggests a lack of succinctness, which is the opposite of what laconic implies. Therefore, the correct choice highlights the essence of being concise and direct, embodying the true nature of a laconic response.