If the trigger is Glock style, its Apex. Hinged, it is "stock".
Remove the sear. If it has any yellow paint on it, it is "stock" sear spring. If not, its Apex.
If your sear is dark grey, its Apex. Shiny, it is "stock".
If the trigger return spring is more cone shaped, its Apex. If it has a slight step down in size at the end that attached to the trigger bar, particularly the last 4 coils, it is "stock".