"We regret to inform you that your request is declined." The tone is:

1. Tone shows the writer's attitude toward the subject and the audience. 2. The sentence uses a polite, impersonal phrase, "We regret to inform you". 3. It keeps a respectful distance from the reader. 4. So the tone is formal, not playful, angry or excited. **Why not the others:** Playful would use jokes, angry would show harsh words, and excited would show enthusiasm, none of which appear. _Source: Wikipedia, "Tone (literature)", section "introduction" (revision 1359726579)_