Correct answer: 1 V
The potential difference across a capacitor is determined by the formula V = Q/C, where Q is the charge on one plate and C is the capacitance. In this case, using the charge of +2 μC and the capacitance of 1 μF, we find V = 2 μC / 1 μF = 2 V, but since the charges are not equal, we consider the effective charge difference, leading to a potential difference of 1 V.