What is the order of increasing energy of the orbitals within a single energy level?

A.     ${\text{d}} < {\text{s}} < {\text{f}} < {\text{p}}$

B.     ${\text{s}} < {\text{p}} < {\text{d}} < {\text{f}}$

C.     ${\text{p}} < {\text{s}} < {\text{f}} < {\text{d}}$

D.     ${\text{f}} < {\text{d}} < {\text{p}} < {\text{s}}$

B