Here it says determine if the two structures below are the same or different compounds. Well, both compounds have two carbons double bonded to each other. Remember, there is no free rotation around that double bond, so things are stuck where they are.
The one on the left has an H and an F next to each other, but the one on the right has 2HS instead next to each other. The one on the left has a BR and an H next to each other, but this one here has a BR and an F next to each other.
We have different groups next to one another in both molecules or both compounds, and we can't rotate around that double bond so that they're the same. Because of this, they would represent different compounds O. Here our answer would be option B.