Question

Which option is It...

Answer 1

I think b is the correct answer

Answer 2

the answer is b

a) n=4 l=0 this represents 4s
b) n=3 l= 1 this represents 3p
c) n=4 l= 2 this represents 4p
d) n=3 l=2 this represents 3d 

by comparing the energy 3p<4s<3d<4p