Cant remember exact rates, i guess it was Full HD with x16 ingame sampling (x16 means 1.6, if i remember right anything below x10 will downgrade picture)
You can try to activate DSR and look at higher resolutions, however playing with settings and overtuning might crash the game too quickly, at least thats how it was by me, so i decided not to tune it and just play it ))
p.s. other video settings didnt affected picture so far, except for some strange feature with "frames" in the name (type of frames processings or something like that). Advisable, gives a lot of fps and almost no visible picture degradation.