The reaction least likely to occur is :
A. `C_(6)H_(6) + HNO_(3)overset(H_(2) SO_(4))to C_(6)H_(5)NO_(2)`
B. `C_(6)H_(6) + H_(2)SO_(4) to C_(6)H_(5)SO_(3)H`
C. `C_(6)H_(6)+ Br_(2) overset(Fe) C_(6)H_(5)Br`
D. `C_(6)H_(6) _ Cl_(2) underset("light")overset(UV)toC_(6)H_(5)Cl`
