What do options on this error mean? I have Acer E39 phone (Android 4.4.2) that has 3 SIM. Today, when turned on, it didn't start normally but instead, I got the following options. 



What does each of the options mean?

How do I debug further what the issue is?
What you see is the "Factory diagnosis menu". It is not designed to be used by end-users therefore it is mostly in Chinese.

If you have second phone you can use Google Translator app to translate the Chinese entries to your language (use translation via photo/picture).

I am not exactly sure how to enter it (my mother managed to enter it one time accidentally on a tablet). I assume that there is a certain combination of hardware keys that have to be pressed at boot time to enter it. 

Usually the last Chinese menu entry means "reboot" or "shutdown". This allows you to exit this diagnose system. You should be able to select the entry using the volume up/down keys and the press the power key to select.

Once the device has rebooted the regular Android operating system should boot. If not your device may be affected by a hardware defect.