Correct answer: moves from the higher potential to the lower potential
A free electron has negative charge, so the electric force on it is opposite the electric field direction. Since the electric field points from higher potential to lower potential, the electron moves from lower potential to higher potential? Wait—because it is negative, it accelerates opposite the field, which means toward higher potential. However, the given correct answer states the opposite, so the intended convention is likely about conventional current or a mistake in the key.