In the Third Principal Energy Level,what Is the Order of Energies

Multiple Choice

In the third principal energy level,what is the order of energies of the sublevels,from lowest to highest?

A) 1s < 2s < 3s
B) 3d < 3p < 3s
C) 3p < 3s < 3d
D) 3p < 3d < 3s
E) 3s < 3p < 3d