The potential difference between two points in a circuit is the difference in electric potential energy per unit charge between those points. In this circuit, the potential difference between points A and B is given as 2 volts.

Option 1 - 2 volts: This is the correct answer given in the question. It states that the potential difference between points A and B is 2 volts.

Option 2 - 3 volts: This option suggests that the potential difference is 3 volts, which is not mentioned in the question. Therefore, this option is incorrect.

Option 3 - 4 volts: Similar to option 2, this option states a potential difference of 4 volts, which is not mentioned in the question. Therefore, this option is incorrect.

Option 4 - None of these: This option suggests that the potential difference between points A and B is not any of the given options. However, the correct answer is provided in option 1, so this option is incorrect.

In conclusion, the potential difference between points A and B in the circuit is 2 volts, as stated in option 1.