Which equation represents a propagation step in the mechanism for the reaction between ethane, \({{\text{C}}_{\text{2}}}{{\text{H}}_{\text{6}}}\), and chlorine, \({\text{C}}{{\text{l}}_{\text{2}}}\), in the presence of sunlight/UV?

A.     \({{\text{C}}_2}{{\text{H}}_6} + {\text{Cl}} \bullet  \to {{\text{C}}_2}{{\text{H}}_5} \bullet  + {\text{HCl}}\)

B.     \({{\text{C}}_2}{{\text{H}}_6} + {\text{Cl}} \bullet  \to {{\text{C}}_2}{{\text{H}}_5}{\text{Cl}} + {\text{H}} \bullet \)

C.     \({\text{C}}{{\text{l}}_{\text{2}}} \to 2{\text{Cl}} \bullet \)

D.     \({{\text{C}}_2}{{\text{H}}_5} \bullet  + {\text{Cl}} \bullet  \to {{\text{C}}_2}{{\text{H}}_5}{\text{Cl}}\)

A