The answer is they follow a patter for valence electrons.
The most appropriate answer is C !! Cs is most electropositive and thus least electronegative !!
When drawing lewis dot diagram structure we consider the number of valence electrons of the atom.Se has six valence electrons since it is in group six thus it Lewis dot diagram is as follows
..
: Se:
Hydrogen is in group one hence has one valence electron.The lewis dot diagram for 2H is therefore
H:H
