Need help with Schedule CA (540) letter from FTB. How do I know if this real tax I owe / challenge it ? It is roughly 5K$.

 Schedule CA (540)- 2019 :  1A- 121,390, 1B-85,322 , 1C-925
Form 540 - 13 -118390 , 14 -85322, 15-33923 , 16-925 , 19-24,919