Electronic configuration of valence shell of four elements, `A,B,C` and D are?
(A) `ns^(2),np^(2)` (D) `ns^(2),np^(3)`
(B) `ns^(2),np^(4)` (D) `ns^(2),np^(5)`
Arrange them in increasing order of `IE_(2)`:
A. `A lt B lt C lt D`
B. `A lt B lt D lt C`
C. `B lt A lt D lt C`
D. `B lt A lt C lt D`
