Which option in smb.conf allows Samba to create Machine Trust Accounts automatically?

The option in smb.conf that allows Samba to create Machine Trust Accounts automatically is the add machine script. This parameter specifies a command that Samba will execute when a new machine attempts to join a Samba domain. By configuring this script, administrators can automate the process of creating the necessary machine trust accounts in the system's user database, eliminating the need for manual account creation. This helps streamline the process of integrating new machines into the network and ensures that they have the appropriate permissions to access resources.

For effective operation, the add machine script typically calls a command that would handle adding the user account with the necessary attributes that distinguish a machine account from regular user accounts in the directory. This automation is particularly useful in environments with many workstations needing to join a domain, as it reduces administrative overhead and minimizes potential errors during manual account creation processes.