Answer:
Point A is at higher potential than point B
Explanation:
Electrons are negatively charged - this means that they are attracted by positive charges and repelled by negative charges.
This also means that they tend to move in a direction opposite to the electric field lines (because electric field lines point away from a positive charge and toward a negative charge). So, they also tend to move from a point at lower potential to a point at higher potential.
In this problem, the electrons flow from point B to point A: therefore, point A must have higher potential than point B.
