Consider the Following Equilibrium

Consider the following equilibrium.

The equilibrium cannot be established when _ _ is/are placed in a 1.0- L container.

A) 0.50 mol O₂ (g) and 0.50 mol SO₃ (g)
B) 0.75 mol SO₂ (g)
C) 0.25 mol of SO₂ (g) and 0.25 mol of SO₃ (g)
D) 1.0 mol SO₃ (g)
E) 0.25 mol SO₂ (g) and 0.25 mol O₂ (g)