Which of the following quantities are independent of the choice of...

The potential at a point and the potential energy of a system are defined relative to a reference point where the potential or potential energy is taken as zero. Therefore, they depend on the choice of the reference point.

The potential difference between two points is the difference in potential between them, given by $\Delta V = V_2 - V_1$. If the reference point is changed, a constant value $C$ is added to the potential at every point. The new potential difference is $(V_2 + C) - (V_1 + C) = V_2 - V_1$. Hence, the potential difference is independent of the choice of zero potential.

Similarly, the change in potential energy of a system is the difference between its final and initial potential energies, given by $\Delta U = U_2 - U_1$. Any constant added due to a change in the reference point cancels out. Thus, the change in potential energy is independent of the choice of zero potential energy.