Which command locks a user account without deleting it?

• A. passwd -l username
• B. usermod -L username
• C. useradd -L username
• D. chage -L username

Answer: (B)

Locking an account means preventing login for that user while keeping the account data intact, so nothing is deleted and you can undo it later. The way to do this directly for an existing account is to apply the lock flag to that user’s account record. The command that does exactly that is the account-management tool with the lock option, which marks the user’s password entry in the system so password-based login is blocked. This is a straightforward, reversible change you can undo with the corresponding unlock.

So, using the account-management command with the lock flag is the best fit here: it locks the account without deleting it and leaves the user’s data and permissions in place for when you want to re-enable access. To re-enable later, you’d unlock with the same tool using the unlock option.

The other options either refer to creating or managing password aging rather than locking an existing account, or are not the standard direct method for suspending an existing user’s login.