Identify the Reaction That Is Described by the Following Equilibrium $\rightarrow$

Identify the reaction that is described by the following equilibrium expression:
K = [H₂]² [O₂] / [H₂O]²

A) 2 H₂ (g) + O₂ (g) $\rightarrow$ 2H₂O (g)
B) H₂O (g) $\rightarrow$ H₂ (g) + O₂ (g)
C) H₂O (g) $\rightarrow$ 2H (g) + O (g)
D) 2H₂O (g) $\rightarrow$ 2 H₂(g) + O₂ (g)