Final answer:
A blog would allow for an informal tone.
Step-by-step explanation:
The document that would allow for an informal tone is a Blog. A blog is a platform where individuals can express their thoughts, opinions, and ideas in a casual and conversational manner. Unlike a job application or résumé, which require a professional and formal tone, or a business letter or proposal, which demand an official tone, a blog allows for a more relaxed and informal writing style.
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