Which one of the following sets of ions represents the collection of isoelectronic species?

Which has maximum $EA$,$EN$ and $IP$ respectively $:-$
$A = 1s^2 \ 2s^2 \ 2p^6$
$B = 1s^2 \ 2s^2 \ 2p^6 \ 3s^2 \ 3p^5$
$C = 1s^2 \ 2s^2 \ 2p^5$
$D = 1s^2 \ 2s^2 \ 2p^6 \ 3s^1$

Consider the following elements arranged in a periodic table segment as shown in the image.
Which of the following is/are true about $A^{\prime}, B^{\prime}, C^{\prime}$ and $D^{\prime}$?
$A$. Order of atomic radii: $B^{\prime} < A^{\prime} < D^{\prime} < C^{\prime}$
$B$. Order of metallic character: $B^{\prime} < A^{\prime} < D^{\prime} < C^{\prime}$
$C$. Size of the element: $D^{\prime} < C^{\prime} < B^{\prime} < A^{\prime}$
$D$. Order of ionic radii: $B^{\prime+} < A^{\prime+} < D^{\prime+} < C^{\prime+}$
Choose the correct answer from the options given below:

Identify the incorrect set$(s)$ among the following periodic trends:

Arrange the elements $N$,$P$,$O$,and $S$ in the order of:
$(i)$ Increasing first ionisation enthalpy.
$(ii)$ Increasing non-metallic character.
Give reasons for the arrangement assigned.

Which group is called the buffer group of the periodic table?