Daniel assists an internal employee with their corporate$-$owned mobile device. Upon further troubleshooting, Daniel notices the employees' phone contacts are currently missing and their corporate account has been logged out. Once logged back into the user's account, Daniel would like to further assist by preventing any data from being lost.

Which of the following would synchronize the user's data using their online corporate account?

a$.$

Emulator

b$.$

File$-$Level Backup

c$.$

Android Package

d$.$

End$-$Of$-$Life $($EOL$)$