Which quantum numbers are required to define an orbital?

Consider the following statements :
$(a)$ Electron density in the $xy$ plane in $3d_{x^2-y^2}$ orbital is zero.
$(b)$ Electron density in the $xy$ plane in $3d_{z^2}$ orbital is zero.
$(c)$ $2s$ orbital has one nodal surface.
$(d)$ For $2p_z$ orbital,$yz$ is the nodal plane.
Select the incorrect statements $:-$

The total number of subshells for which $(n + l) = 7$ is .......

What is the maximum number of electrons accommodated in a subshell having azimuthal quantum number,$\ell=2$?

Which of the following sets of quantum numbers is correctly matched?

Two electrons occupying the same orbital are distinguished by