Which one of the following actions can establish an Active Directory connection?

Establishing an Active Directory connection typically involves using a specific action designed to communicate with the Active Directory service. The action of "Connect to server" is fundamentally about initiating a connection to the Active Directory or any server that holds the directory service. This connection is essential for performing other operations like creating users, managing groups, or querying the directory information.

When "Connect to server" is executed, it sets up the necessary authentication and establishes a session, enabling subsequent actions to interact with Active Directory data. Other actions, like creating a user, often depend on an existing connection to function correctly, but they themselves do not initiate a connection.

Therefore, "Connect to server" is the correct action to establish the initial connection required for further operations with Active Directory.