Seeing a wall of force

[Dungeon-noob]

Option 1; it doesn't say it blocks line of sight, so not option 2. It does say the wall is invisible, so option 1 is supported by RAW. Option 3 is what i imagined myself, and what i would think is the most fun, since invisible walls can get frustrating really fast.


Edit, reread the spell and had to change my answer