For the reaction: 2H₂O(g) ↔ 2H₂(g) + O₂(g) Keq-H₂O₂, what are the correct values of x, y, and z for the equilibrium expression to be correct? Select one or more:

a) x = 2, y = 2, z = 1
b) x = 2, y = 1, z = 2
c) x = 1, y = 2, z = 2
d) x = 1, y = 1, z = 1