Scratch in sreen
By the looks of that picture, it's hard for me to believe that the scratch is not on the outside of the protective plexiglass screen. However, you can remove the protective screen w/o negative effect of the picture. In fact, it will probably reduce the glare from light on the screen. If, in fact, the scratch is still seen w/o the protective screen installed, then it is the lenticular screen that is scratched.
The lenticular screen is the one with the vertical grooves from top to bottom in it. The fresnal is the back screen that appears to have been lathed in a circular pattern.