Which of the following is NOT a prerequisite for properly installing Exchange?

The correct answer is C, as upgrading to Windows 11 is not a prerequisite for properly installing Microsoft Exchange. Exchange has specific system and software requirements, including operating systems that support it, but it does not mandate the latest version like Windows 11; it is generally compatible with certain server editions of Windows.

Setting a static IP address, installing Active Directory, and assigning a proper computer name are all critical steps for a successful Exchange installation. A static IP ensures stable communication, while Active Directory is essential for managing user permissions and identities within the Exchange environment. The computer name is important for identifying the server within the network and for proper integration with other services. Thus, while the other options are integral to preparing the server for Exchange, upgrading to Windows 11 does not fit into the necessary prerequisites for the installation.