The set representing the correct order of first ionisation potential is

Given below are two statements:
Statement $I$: The decrease in first ionization enthalpy from $B$ to $Al$ is much larger than that from $Al$ to $Ga$.
Statement $II$: The $d$ orbitals in $Ga$ are completely filled.
In the light of the above statements,choose the most appropriate answer from the options given below:

The correct order of second ionisation potentials $(IP)$ of $Ca$,$Ba$ and $K$ is

The first four ionisation energy values of an element are $191$,$578$,$872$ and $5962 \ kcal$. The number of valence electrons in the element is :-

The correct order of $C$, $N$, $O$ and $F$ in terms of second ionisation potential is

Triad-$I$ $[N^{3-}, O^{2-}, Na^{+}]$
Triad-$II$ $[N^{+}, C^{+}, O^{+}]$
Choose the species of lowest $IP$ from triad-$I$ and highest $IP$ from triad-$II$ respectively.