I'd assume it would be C because the two electrons present in the l = 2 subshell (p) are degenerate. As a result the energy needed to remove an electron in a lower subshell (l=1) would be substantially different compared to the other subshell.
The electron configuration that corresponds to the valence electrons of an element for which there is an especially large jump between the second and third ionization energies is ns^2.
The valence electron configuration of an atom refers to the arrangement of electrons on the outermost shell of the atom.
Recall that a large jump in ionization energy occurs when electrons are removed from inner shells of the atom.
If we study our options closely, we will discover that option A has only two electrons in the valence shell (ns^2).
This means that the third ionization energy involves removing electrons from an inner shell which leads to large jump.
