Which type of message is not informed of the other receivers?

• A. Single
• B. Multiple Address
• C. Book
• D. GENADMIN

Answer: (C)

In the context of communication types, the "Book" message is designed to be a more formal and static form of communication that provides detailed information for reference, typically distributed to a larger audience or stored for future access. Unlike other message types, it does not directly inform other receivers in real-time or acknowledge receipt by multiple parties.

Single messages are designed for direct communication with one specific recipient, while Multiple Address messages are intended to reach several recipients but maintain awareness among all designated parties. GENADMIN messages, which are typically used for general administrative communication, can inform a wide audience and are structured to ensure that information is relayed to all intended receivers efficiently.

The "Book" message, in contrast, lacks the interactive or immediate dissemination aspects while still serving the purpose of conveying information, making it distinct in this regard.