In which of the following is the electron gain enthalpy of elements correctly arranged?

Which of the following is correct for the electron affinity of halogens?

In which of the following pairs,electron gain enthalpies of constituent elements are nearly the same or identical?
$A$. $Rb$ and $Cs$
$B$. $Na$ and $K$
$C$. $Ar$ and $Kr$
$D$. $I$ and $At$
Choose the correct answer from the options given below.

Which of the following statements is correct?

Electronic configurations of four elements $A, B, C$ and $D$ are given below :
$(A)$ $1s^2 2s^2 2p^6$
$(B)$ $1s^2 2s^2 2p^4$
$(C)$ $1s^2 2s^2 2p^6 3s^1$
$(D)$ $1s^2 2s^2 2p^5$
Which of the following is the correct order of increasing tendency to gain electron :

The second electron affinity of an element is ...