You suspect that a customer’s MacBook Pro is failing to connect to a network because of a setting. Which technique is the most efficient way for you to test the
MacBook Pro with default network settings?

A.
Create a new location in System Preferences > Network.

B.
Start the MacBook Pro from an external disk, or netboot image.

C.
Create a new user in the Users & Groups preferences pane and test in that user.

D.
Erase the customer’s hard disk, reinstall OS X Mountain Lion, then create a new user.