What is the coefficient of ${\rm{F}}{{\rm{e}}_3}{{\rm{O}}_4}$ when the following equation is balanced using the lowest whole numbers?

__ ${\text{Al(s)}} +$ __ ${\text{F}}{{\text{e}}_3}{{\text{O}}_4}({\text{s)}} \to$ __ ${\text{A}}{{\text{l}}_2}{{\text{O}}_3}({\text{s)}} +$ __ ${\text{Fe(s)}}$

A.     2

B.     3

C.     4

D.     5

B