A technician has decided to upgrade all users’ iPhones to the latest model. Which of the following is the FIRST thing the technician should advise the users to do with the old phones before turning them in?
A. Back up the mobile data with a cloud backup service.
B. Enable remote wipe to clear all personal and corporate data.
C. Go into the device settings to remove personal customizations.
D. Factory reset the old phones to ensure the data is no longer on the device.