Please help fast fast

given

the sequences are;5,11,17,23

now we have difference between first series and second seris is 6

so,tn=a+(n_1)×d (where a=1stseries,n is the

termand d is diff betwn 1st

and 2nd series)

so,tn=5+(n_1)×6

=5+6n_6

=6n_1n th term

now;

t1=6×1_1=5

t2=6×2_1=11

t3=6×3_1=17

t4=6×4_1=23

therefore ; the nth term of the given sequence is ; 6th_1.

it's c. elements are placed in rows based on how may valencies electrons have.