Which token marks the end of a message in GPT-4?

• A. <|startoftext|>
• B. <|endoftext|>
• C. <|endofmessage|>
• D. <|eot|>

Answer: (B)

End-of-text is the signal that finishes a message. It marks the boundary after the content and tells the model to stop generating, effectively ending that piece of text. In many teaching contexts for GPT-4, the token string <|endoftext|> is used as this end marker, which is why it’s the best choice here. The start-of-text marker signals the opposite boundary—the beginning of content—so it wouldn’t indicate the end. Other options like end-of-message or a shorter end token aren’t the standard termination signal in this setup, so they’re not the correct choice for marking the end of a message.