In which of the following electronic configurations of an element is there a very large difference between the second and third ionization energy?

The correct decreasing order of first ionisation enthalpies of five elements of the second period is

Given below are two statements:
Statement $(I)$: The first ionisation enthalpy of the elements $Na$, $Mg$, $Cl$ and $Ar$ follows the order $Na > Mg > Cl > Ar$.
Statement $(II)$: Among $Ca$, $Al$, $Fe$ and $B$, the third ionisation enthalpy is very high for $Ca$.

Consider the following changes:
$M_{(s)} \to M_{(g)}$ ........$(1)$
$M_{(s)} \to M^{2+}_{(g)} + 2e^-$ .......$(2)$
$M_{(g)} \to M^{+}_{(g)} + e^-$ .........$(3)$
$M^{+}_{(g)} \to M^{2+}_{(g)} + e^-$ .........$(4)$
$M_{(g)} \to M^{2+}_{(g)} + 2e^-$ ..........$(5)$
The second ionization energy of $M$ could be calculated from the energy values associated with:

The first ionisation energies (in $kJ \ mol^{-1}$) of four consecutive elements of the second period are given in the options. The first ionisation energy of nitrogen is

What are the various factors due to which the ionization enthalpy of the main group elements tends to decrease down a group?