A helpdesk technician explains to a curious user what Android Recovery Mode is used for. Which of the following is a legitimate use case for entering Android Recovery Mode?

• A.Recovery Mode is where APN and carrier settings are edited (the radio configuration lives outside the main OS), and the technician reaches for it when the handset fails to attach to the network
• B.Recovery Mode drops the technician into a root shell (adbd runs unrestricted there), and system partition files can be edited in place even on a device whose bootloader is locked
• C.Recovery Mode installs individual app APKs from a memory card (the package manager runs in a reduced form), and the technician uses it when the Play Store is unable to reach the handset
• D.Recovery Mode allows applying full OTA update packages (sideloading update.zip), performing factory resets, and wiping the cache partition without booting the main Android OS