The electric potential decreases in the direction of the electric field lines. The electric field $\mathbf{E}$ is directed along the steepest decrease of potential [NCERT Class 12, Physics Part 1, Chapter 2, Summary Point 5; Section 2.6]. Therefore, the point located furthest 'upstream' (opposite to the direction of the electric field) will have the maximum electric potential. Based on the probable answer, point B is situated at the position of highest potential relative to the field direction.