Given That
S(g)+ O₂(g) $\to$ SO₂(g) $~~~~~~~~$ $~~~~~~~~$ $\Delta$ _rG ^$\circ$ = -300

Given that
S(g) + O₂(g) $\to$ SO₂(g) $~~~~~~~~$$~~~~~~~~$$\Delta$ _rG ^$\circ$ = -300.1 kJ/mol-rxn
2 S(g) + 3 O₂(g) $\to$ 2 SO₃(g) $~~~~~~~~$$\Delta$ _rG ^$\circ$ = -742.1 kJ/mol-rxn
Calculate $\Delta$ _fG ^$\circ$ of the following reaction:
SO₂(g) + 1/2 O₂(g) $\to$ SO₃(g)

A) -1042.2 kJ/mol-rxn
B) -71.0 kJ/mol-rxn
C) +2.47 kJ/mol-rxn
D) +71.0 kJ/mol-rxn
E) +1042.2 kJ/mol-rxn