Of the ways listed, which is the best way to temporarily suspend a user’s ability to interactively login?

A.
Changing the user’s UID.

B.
Changing the user’s password.

C.
Changing the user’s shell to /bin/false.

D.
Removing the user’s entry in /etc/passwd.

E.
Placing the command logout in the user’s profile.

Explanation:
CAUTION: Simply using /bin/false as someone’s shell does not keep them from using said account to authenticate over ssh and using non-shell tools such as port forwarding. A default configuration in sshd will often allow tunneling and other non-shell activity.