For the Reaction SO₂(g) + NO₂(g) SO₃(g) + NO(g)

For the reaction SO₂(g) + NO₂(g) SO₃(g) + NO(g) , the equilibrium constant K_c is 18.0 at 1200ºC. If 1.0 mole of SO₂ and 2.0 moles of NO₂ are placed in a 20.0-L container, what concentration of SO₃ will be present at equilibrium?

A) 0.048 mol/L
B) 0.11 mol/L
C) 0.95 mol/L
D) 2.22 mol/L
E) 18 mol/L