Which Reagent(s)would You Use to Carry Out the Following Transformation $\rightarrow$

Which reagent(s) would you use to carry out the following transformation? toluene -- $\rightarrow$ benzoic acid

A) Br₂,heat,and light
B) Cl₂,FeCl₃
C) KMnO₄,OH^-,heat (then H₃O⁺)
D) HNO₃/H₂SO₄
E) SO₃/H₂SO₄