Which of the following orbitals is impossible?

The electronic configuration of the element with atomic number $24$ is:

Statement $A$: In a potassium atom,the $19^{th}$ electron enters the $4s$-orbital instead of the $3d$-orbital.
Reason $R$: The $(n + l)$ rule is followed to determine the minimum energy of an orbital.

The radial probability distribution curve for an orbital comprises of $3$ maxima. If the orbital has $3$ angular nodes as well,then the orbital can be:

What is the total number of unpaired electrons present in the observed electronic configuration of $Cr$ $(Z=24)$?

For a given atomic orbital,$n = 3$. What are the possible values of $l$ and $m_l$?