I need help please. I’m between B or C and many responses have been B but I think that’s for if NO would be added and not SO3.....so idk I’m confused apex

Answer:
C. More NO₂ and SO₂ would form.
Explanation:
This is an example of Le Châtelier's principle. The reaction will try to seek balance, so if you add something to the right side, the reaction will reverse until both sides are balanced again. So adding SO₃ would cause more NO₂ and SO₂ to form.