A security engineer testing an Android device notices the device shows a red warning screen at boot saying 'Your device is corrupt. It can no longer be trusted.' What does this indicate?

• A.The red screen is the standard first-boot notice on hardware where the OEM ships an unlocked bootloader (a design choice on developer-edition units), and it has no bearing on the integrity of the running image: the engineer can dismiss it and carry on with the assessment. It clears once the device completes its first Play System Update.
• B.The red screen means Android Verified Boot found the dm-verity hash tree intact and could not reach Google's attestation endpoint (the handset was offline for the whole of that boot), and the boot state was reported unknown instead of verified: the engineer should put the device back on the corporate network and reboot it once. Repeated offline boots keep the warning on screen even on a wholly unmodified handset, and the vbmeta digest in the MDM console will confirm the system partition still matches the shipped image.
• C.