Which of the following elements can an Organizational Unit (OU) contain?

An Organizational Unit (OU) is a key component of a directory service, like Active Directory, used for managing a network's structure and organization. The correct option states that an OU can contain users, groups, and applications. This reflects the primary purpose of an OU, which is to create a logical hierarchy for better management and organization of various directory objects.

OUs are versatile and can house a variety of object types. In addition to user accounts—where individual user profiles and credentials are stored—OUs can also contain groups, which serve as collections of user accounts that can be managed collectively. Moreover, applications relevant to the organization may also be placed within an OU, facilitating easier access management and application deployment.

The other options are limited in scope and do not accurately capture the full range of what an OU can contain. For instance, stating that an OU can only have user accounts restricts its functionality and overlooks its ability to manage groups and applications effectively. Similarly, the choices referencing only security settings or only computers and printers fail to recognize the comprehensive organizational role an OU plays in managing various types of objects within a network. Thus, the breadth of content that an OU can hold is critical for effective account and network management.