Observe the given figure showing the boundary surface diagrams of...

Shape P is spherically symmetric, which corresponds to an $s$ orbital. For an $s$ orbital, the azimuthal quantum number is $l = 0$. Thus, A matches with 3.

Shape Q has two lobes oriented along the x-axis, which corresponds to a $p_x$ orbital. For a $p$ orbital, $l = 1$. Thus, B matches with 1.

Shape R has four lobes lying in the xz plane between the x and z axes, which corresponds to a $d_{xz}$ orbital. For a $d$ orbital, $l = 2$. Thus, C matches with 4.

Shape S has two lobes along the z-axis and a donut-shaped ring in the xy plane, which corresponds to a $d_{z^2}$ orbital. For a $d$ orbital, $l = 2$. Thus, D matches with 2.

The correct matching is (A)-(3), (B)-(1), (C)-(4), (D)-(2).

Answer: (A)-(3), (B)-(1), (C)-(4), (D)-(2)