Which one of the following actions do you have to use to create an Active Directory organizational unit?

To create an Active Directory organizational unit, the action that must be used is to create an object. This is because the Active Directory structure is built upon a hierarchical model where various elements, such as users, groups, and organizational units, are considered "objects."

An organizational unit (OU) specifically is a container used to organize users, groups, computers, and other organizational units, which helps manage the directory more effectively. The action to create an object allows you to define various attributes for the new OU, specifying its name and other related properties.

Establishing a connection is necessary for accessing the Active Directory, but it does not directly pertain to the creation of an organizational unit. Similarly, creating a group addresses a different function altogether, which is to group users and assign permissions collectively. Therefore, the action to create an object is the appropriate choice for establishing an organizational unit in Active Directory.