Which of the following tools is generally used for managing distribution groups?

The choice of Active Directory Users and Computers (ADUC) as the tool for managing distribution groups is appropriate because ADUC is specifically designed for managing user accounts, groups, and other objects within Active Directory. It provides a graphical user interface that allows administrators to easily create, modify, and delete distribution groups, assign permissions, and manage user memberships.

ADUC is integral to the administration of Active Directory environments and offers functionalities that are essential for defining group properties, including security settings and email functionalities in conjunction with Exchange. This makes it the most effective and widely used tool for the task in question.

The other options provided do not serve this specific purpose. For example, File Explorer is primarily for file management and navigation of the file system, while Windows Defender focuses on security and malware protection. Although the Exchange Management Console (EMC) could manage distribution lists associated with mailboxes, ADUC is the go-to tool for comprehensive management of distribution groups within Active Directory.