Which of the following installation types would require the use of an answer file to install the OS?

An unattended installation uses an answer file (such as autounattend.xml for Windows) that contains all required setup parameters - language, partition layout, product key, and user settings - allowing the OS to install without any technician interaction. This is the defining characteristic that distinguishes it from interactive installation types.

A clean installation wipes the drive and installs the OS fresh but still requires manual input through the standard interactive setup wizard.

A repair installation attempts to fix an existing OS installation using the current setup, prompting the technician interactively rather than consuming an answer file.

An upgrade installation preserves existing data and settings while updating the OS version and follows an interactive guided process, not an answer file.