A thin, flat annular disk has an inner radius \(a\), an outer radius \(b\), and a uniform positive surface charge density \(\sigma\). The disk lies in the \(xy\)-plane centered at the origin, and point \(P\) is located on the central \(z\)-axis at a distance \(z\) from the center of the disk. Which of the following expressions represents the correct integral setup to determine the electric potential \(V\) at point \(P\) relative to zero potential at infinity?