Remote wipe is the best option to prevent unauthorized access to data when a mobile device is lost or stolen—especially if the user is unaware of the loss. It allows administrators or mobile device management (MDM) systems to remotely erase all data on the device, rendering it unusable for unauthorized users.

A. Encryption protects the data, but if the device remains powered and logged in, it may still be accessible.

C. Geofencing can restrict features based on location but does not erase data.

D. Facial recognition helps secure access but can be bypassed in some cases or fail in practical situations.