Users of mobile devices on your network need to connect to the corporate network when they are away from the office using a VPN app. A user complains that he is unable to open the app. The app won't launch even after he turned the tablet off and back on again. What should he do next?

Rebooting is the first thing to do if an app won't load. Try uninstalling the app and then reinstalling the app if that doesn't work. Make sure to check the vendor's site for any previously reported problems and solutions. Cycling the power means turning the device off and on again. That was already done. A reset to factory defaults wipes the phone. That would be the very last solution you would try to fix a phone problem. You cannot force stop the app because after that it won't open.