Which of the Following Is a Balanced Equation for the Combination

Multiple Choice

Which of the following is a balanced equation for the combination reaction that occurs when sulfur dioxide gas, SO₂, reacts with oxygen gas to form sulfur trioxide gas?

A) 3SO₂(g) + 2O₂(g) → 3SO₃(g)
B) SO₂(g) + O₂(g) → SO₃(g)
C) SO₂(g) + O₂(g) → SO₄(g)
D) 2SO₂(g) + 2O₂(g) → 2SO₃(g)
E) 2SO₂(g) + O₂(g) → 2SO₃(g)