The reaction conditions leading to the best yield of `C_(2)H_(5)Cl` are
A. `C_(2) H_(6) ("Excess") + Cl_(2) overset(U. V. "light")(rarr)`
B. `C_(2) H_(6) + Cl_(2) ("Excess") underset("room temp.")overset("Dark")(rarr)`
C. `C_(2) H_(6) + Cl_(2) ("Excess") overset(U.V."light")(rarr)`
D. `C_(2) H_(6) + Cl_(2) overset(U.V."light")(rarr)`