Which of the following steps prevents a user from obtaining an interactive login session?

Changing a user's login shell to `/bin/false` (or `/sbin/nologin`) with `chsh -s /bin/false <username>` effectively prevents them from starting an interactive shell session, as `/bin/false` simply exits immediately. This is a common method for disabling interactive logins for service accounts.

Setting a user's UID to 0 would grant them root privileges, not prevent them from logging in; it would give them full system access.

Removing a user from a specific group like `staff` only affects their group-based permissions, not their ability to log in interactively.

`/etc/noaccess` is not a standard Unix/Linux mechanism for preventing user logins; this might be specific to other Unix variants or non-standard configurations.

Creating a `.nologin` file in a user's home directory does not universally prevent interactive login sessions; the `/etc/nologin` file typically applies globally to prevent *all* non-root users from logging in.