You Are Preparing to Upgrade Windows 7 to Windows 10

You are preparing to upgrade Windows 7 to Windows 10 but you are going to be cautious and make a backup of your system before proceeding with the installation. Which of the following should NOT be a consideration for performing your backup.

A) close all files to ensure all files are backed up
B) be certain you can restore the backup in both the old and new OS
C) select only the data files for backup since the OS files and applications will not be affected by the upgrade
D) make sure you have suitable media to store the backup on