Two Moles of SO₂ , Two Moles of O₂, and Two

Two moles of SO₂ , two moles of O₂, and two moles of SO₃ are placed in a one liter flask. If K c for the reaction 2 SO₂ (g) + O₂(g) 2 SO₃(g) is 0.50 at this temperature, what occurs in the flask as equilibrium is approached?

A) [SO₃] increases
B) [O₂] increases
C) [SO₂] increases
D) All concentrations remain constant since the system is at equilibrium.
E) The equilibrium concentrations of [O₂] and [SO₂] are very small.