Which of the following is a formal communication?

A formal communication typically refers to communication that follows a structured and official format within an organization. An email from the department is considered a formal communication because it is written, documented, and likely follows established protocols for communication within the organization. This type of communication is often used for official announcements, reports, requests, or updates that need to be documented and maintained for reference.

While options A, B, and D may also be forms of communication within a workplace, they are not necessarily formal. Chat messages and verbal updates, although important for quick exchanges of information, are generally informal and may lack the level of formality and accountability associated with formal communication. A team meeting agenda, while more formal than a chat message or verbal update, may not be as formal as an official email from the department, which typically carries more weight in terms of documentation and accountability.